Commit b4b55cda58 (Refine the way to release PCI IRQ resources)
introduced a regression in the PCI IRQ resource management by causing
the IRQ resource of a device, established when pci_enabled_device()
is called on a fully disabled device, to be released when the driver
is unbound from the device, regardless of the enable_cnt.
This leads to the situation that an ill-behaved driver can now make a
device unusable to subsequent drivers by an imbalance in their use of
pci_enable/disable_device(). That is a serious problem for secondary
drivers like vfio-pci, which are innocent of the transgressions of
the previous driver.
Since the solution of this problem is not immediate and requires
further discussion, revert commit b4b55cda58 and the issue it was
supposed to address (a bug related to xen-pciback) will be taken
care of in a different way going forward.
Reported-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Commit 7d78cbefaa (serial: 8250_dw: add ability to handle
the peripheral clock) introduces handling for a second clk
to 8250_dw.c which is the driver also for LPSS UART. The
second clk forces us to provide identifier (con_id) for the
clkdev we create.
This fixes an issue where 8250_dw.c is getting the same
handler for both clocks.
Fixes: 7d78cbefaa (serial: 8250_dw: add ability to handle the peripheral clock)
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: 3.17+ <stable@vger.kernel.org> # 3.17+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Report the actual error code from acpi_bus_register_driver(), it may
help future debugging (typically ENODEV as previously reported, but the
unusual cases are where it may help most).
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
i915.ko depends upon the acpi/video.ko module and so refuses to load if
ACPI is disabled at runtime if for example the BIOS is broken beyond
repair. acpi/video provides an optional service for i915.ko and so we
should just allow the modules to load, but do no nothing in order to let
the machines boot correctly.
Reported-by: Bill Augur <bill-auger@programmer.net>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: All applicable <stable@vger.kernel.org>
Acked-by: Aaron Lu <aaron.lu@intel.com>
[ rjw: Fixed up the new comment in acpi_video_init() ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Some BIOSes report incorrect length for ACPI address space descriptors,
so relax the checks to avoid regressions. This issue has appeared several
times as:
3162b6f0c5 ("PNPACPI: truncate _CRS windows with _LEN > _MAX - _MIN + 1")
d558b483d5 ("x86/PCI: truncate _CRS windows with _LEN > _MAX - _MIN + 1")
f238b414a7 ("PNPACPI: compute Address Space length rather than using _LEN")
48728e0774 ("x86/PCI: compute Address Space length rather than using _LEN")
Please refer to https://bugzilla.kernel.org/show_bug.cgi?id=94221
for more details and example malformed ACPI resource descriptors.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=94221
Fixes: 593669c2ac (x86/PCI/ACPI: Use common ACPI resource interfaces ...)
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Tested-by: Dave Airlie <airlied@redhat.com>
Tested-by: Prakash Punnoor <prakash@punnoor.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
- Revert a recent ACPI LPSS driver commit that prevented the touchpad
driver from loading on Dell XPS13 (Jarkko Nikula).
- Make the ACPI LPSS driver disable the I2C controllers and deassert
SPI host controllers resets at startup on Intel BayTrail and Braswell
SoCs in case they have been left in wrong states by the platform
firmware which then may casuse fatal controller driver failures during
resume from hibernation (Mika Westerberg).
- Make two recently added ACPI EC messages look better (Scot Doyle).
- Reduce the printk level of a recently added debug message related to
ACPI resources that may become noisy in some cases (Rafael J Wysocki).
- Add a new ACPI backlight blacklist entry for Samsung Series 9
(900X3C/900X3D/900X3E/900X4C/900X4D) laptops where the native backlight
interface doesn't work while the ACPI based one does (Jens Reyer).
- Make the PNP sybsystem's core code use __request_region() followed by
__release_region() instead of __check_region() which then will allow
us to get rid of the latter as it has no more users (Jakub Sitnicki).
- Fix a build breakage and an issue with two __init functions that may be
called after initialization in the s3c cpufreq driver (Arnd Bergmann).
- Make the powernv cpuidle driver read target_residency values for idle
states from a Device Tree (as we have the suitable DT bindings for that
now) and improve the parsing of the powermgmt DT node in that driver
(Preeti U Murthy).
/
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Merge tag 'pm+acpi-3.20-rc1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull one more batch of power management and ACPI updates from Rafael Wysocki:
"These are mostly fixes on top of the previously merged recent PM and
ACPI material.
First, one commit that broke the ACPI LPSS (Low-Power Subsystem)
driver on a Dell box is reverted and there are two stable-candidate
fixes for that driver. Another fix cleans up two recently added ACPI
EC messages that look odd and the printk level of a noisy debug
message in the core ACPI resources handling code is reduced.
In addition to that we have two stable-candidate fixes for the s3c
cpufreq driver, two cpuidle powernv driver updates related to Device
Trees and a PNP subsystem cleanup that will allow us to get rid of
some old ugliness going forward. Also there is a new blacklist entry
for the ACPI backlight code.
Specifics:
- Revert a recent ACPI LPSS driver commit that prevented the touchpad
driver from loading on Dell XPS13 (Jarkko Nikula).
- Make the ACPI LPSS driver disable the I2C controllers and deassert
SPI host controllers resets at startup on Intel BayTrail and
Braswell SoCs in case they have been left in wrong states by the
platform firmware which then may casuse fatal controller driver
failures during resume from hibernation (Mika Westerberg).
- Make two recently added ACPI EC messages look better (Scot Doyle).
- Reduce the printk level of a recently added debug message related
to ACPI resources that may become noisy in some cases (Rafael J
Wysocki).
- Add a new ACPI backlight blacklist entry for Samsung Series 9
(900X3C/900X3D/900X3E/900X4C/900X4D) laptops where the native
backlight interface doesn't work while the ACPI based one does
(Jens Reyer).
- Make the PNP sybsystem's core code use __request_region() followed
by __release_region() instead of __check_region() which then will
allow us to get rid of the latter as it has no more users (Jakub
Sitnicki).
- Fix a build breakage and an issue with two __init functions that
may be called after initialization in the s3c cpufreq driver (Arnd
Bergmann).
- Make the powernv cpuidle driver read target_residency values for
idle states from a Device Tree (as we have the suitable DT bindings
for that now) and improve the parsing of the powermgmt DT node in
that driver (Preeti U Murthy)"
* tag 'pm+acpi-3.20-rc1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpuidle: powernv: Avoid endianness conversions while parsing DT
cpufreq: s3c: remove last use of resume_clocks callback
cpufreq: s3c: remove incorrect __init annotations
ACPI / LPSS: Deassert resets for SPI host controllers on Braswell
ACPI / LPSS: Always disable I2C host controllers
ACPI / resources: Change pr_info() to pr_debug() for debug information
ACPI / video: Disable native backlight on Samsung Series 9 laptops
cpuidle: powernv: Read target_residency value of idle states from DT if available
Revert "ACPI / LPSS: Remove non-existing clock control from Intel Lynxpoint I2C"
ACPI / EC: Remove non-standard log emphasis
PNP: Switch from __check_region() to __request_region()
Pull thermal managament updates from Zhang Rui:
"Specifics:
- Abstract the code and introduce helper functions for all int340x
thermal drivers. From: Srinivas Pandruvada.
- Reorganize the ACPI LPAT table support code so that it can be
shared for both ACPI PMIC driver and int340x thermal driver.
- Add support for Braswell in intel_soc_dts thermal driver.
- a couple of small fixes/cleanups for step_wise governor and int340x
thermal driver"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
Thermal/int340x_thermal: remove unused uuids.
thermal: step_wise: spelling fixes
thermal: int340x: fix sparse warning
Thermal/int340x: LPAT conversion for temperature
ACPI / PMIC: Use common LPAT table handling functions
ACPI / LPAT: Common table processing functions
thermal: Intel SoC DTS: Add Braswell support
Thermal/int340x/int3402: Provide notification support
Thermal/int340x/processor_thermal: Add thermal zone support
Thermal/int340x/int3403: Use int340x thermal API
Thermal/int340x/int3402: Use int340x thermal API
Thermal/int340x: Add common thermal zone handler
On some Braswell systems BIOS leaves resets for SPI host controllers
active. This prevents the SPI driver from transferring messages on wire.
Fix this in similar way that we do for I2C already by deasserting resets
for the SPI host controllers.
Reported-by: Yang A Fang <yang.a.fang@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: 3.17+ <stable@vger.kernel.org> # 3.17+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
On Baytrail and Braswell the BIOS might leave the I2C host controllers
enabled, probably because it uses them for its own purposes. This is fine
in normal cases because the I2C driver will disable the hardware when it
is probed anyway.
However, in case of suspend to disk it is different story. If the driver
happens to be compiled as a module the boot kernel never loads the driver
thus leaving host controllers enabled upon loading the hibernation image.
The I2C host controller interrupt mask register has default value of 0x8ff,
in other words it has most of the interrupts unmasked. When combined with
the fact that the host controller is enabled, the driver immediately starts
getting interrupts even before its resume hook is called (once IO-APIC is
resumed). Since the driver is not prepared for this it will crash the
kernel due to NULL pointer derefence because dev->msgs is NULL.
Unfortunately we were not able to get full backtrace to from the console
which could be reproduced here.
In order to fix this even when the driver is compiled as module, we disable
the I2C host controllers in byt_i2c_setup() before devices are created.
Reported-by: Yu Chen <yu.c.chen@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: 3.17+ <stable@vger.kernel.org> # 3.17+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Annoying and noisy ACPI debug messages are printed with pr_info()
after the recent ACPI resources handling rework. Replace the
pr_info() with pr_debug() to reduce to noise level.
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Add video_disable_native_backlight quirk for SAMSUNG 900X3C/900X3D/
900X3E/900X4C/900X4D laptops.
The native intel backlight controls do not work correctly on SAMSUNG
Series 9 (900X3C/900X3D/900X3E/900X4C/900X4D) laptops:
One machine has an completely dimmed (= black) display after boot at the
GDM login screen and brightness controls work only between 0 and 5%
(= no effect).
Another machine has the same brightness control issues if an external
HDMI monitor is or gets connected, although the initial brightness is
ok.
After login to Gnome both machines always work fine.
Tested on both machines.
Link: https://bugs.freedesktop.org/show_bug.cgi?id=87286
Link: https://bugs.debian.org/772440
Signed-off-by: Jens Reyer <jens.reyer@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Revert commit b893e80e31 ("ACPI / LPSS: Remove non-existing clock control
from Intel Lynxpoint I2C") because it causes touchpad to not load on Dell
XPS13.
Regression is a clear indication that not only some early prototype version
of Lynxpoint I2C but also newer versions can be doing clock gating even
documentation does not state it.
Therefore it is best to revert since this clock gating haven't caused known
issues on those Lynxpoint version which don't do clock gating.
Reported-by-and-tested-by: Chris Rorvick <chris@rorvick.com>
Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Remove unusual pr_info() visual emphasis introduced in ad479e7f47
"ACPI / EC: Introduce STARTED/STOPPED flags to replace BLOCKED flag".
Signed-off-by: Scot Doyle <lkml14@scotdoyle.com>
[ rjw: Change pr_info() to pr_debug() too in those places. ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Add an ->enter_freeze callback routine, acpi_idle_enter_freeze(), to
the ACPI cpuidle driver and point ->enter_freeze to it for all the
C2-type and C3-type states that don't need to fall back to C1
(which may be halt-induced and that will re-enable interrupts on
exit from idle, which ->enter_freeze cannot do).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
- Revert two ACPI EC driver commits, one that broke system suspend
on Acer Aspire S5 and one that depends on it (Rafael J Wysocki).
- Fix a typo leading to an incorrect check in the exynos-ppmu devfreq
driver (Dan Carpenter).
- Add support for one more Broadwell CPU model to intel_idle (Len Brown).
- Fix an obscure problem with state transitions related to interrupts
in the speedstep-smi cpufreq driver (Mikulas Patocka).
- Remove some unnecessary messages related to the "out of memory"
condition from the core PM code (Quentin Lambert).
- Update turbostat parameters and documentation, add support for
one more Broadwell CPU model to it and modify it to skip
printing disabled package C-states (Len Brown).
/
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Merge tag 'pm+acpi-3.20-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull more ACPI and power management updates from Rafael Wysocki:
"These are two reverts related to system suspend breakage by one of a
recent commits, a fix for a recently introduced bug in devfreq and a
bunch of other things that didn't make it into my previous pull
request, but otherwise are ready to go.
Specifics:
- Revert two ACPI EC driver commits, one that broke system suspend on
Acer Aspire S5 and one that depends on it (Rafael J Wysocki).
- Fix a typo leading to an incorrect check in the exynos-ppmu devfreq
driver (Dan Carpenter).
- Add support for one more Broadwell CPU model to intel_idle (Len Brown).
- Fix an obscure problem with state transitions related to interrupts
in the speedstep-smi cpufreq driver (Mikulas Patocka).
- Remove some unnecessary messages related to the "out of memory"
condition from the core PM code (Quentin Lambert).
- Update turbostat parameters and documentation, add support for one
more Broadwell CPU model to it and modify it to skip printing
disabled package C-states (Len Brown)"
* tag 'pm+acpi-3.20-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
PM / devfreq: event: testing the wrong variable
cpufreq: speedstep-smi: enable interrupts when waiting
PM / OPP / clk: Remove unnecessary OOM message
Revert "ACPI / EC: Add query flushing support"
Revert "ACPI / EC: Add GPE reference counting debugging messages"
tools/power turbostat: support additional Broadwell model
intel_idle: support additional Broadwell model
tools/power turbostat: update parameters, documentation
tools/power turbostat: Skip printing disabled package C-states
__FUNCTION__ hasn't been treated as a string literal since gcc 3.4, so
this only helps people who only test-compile using 3.3 (compiler-gcc3.h
barks at anything older than that). Besides, there are almost no
occurrences of __FUNCTION__ left in the tree.
[akpm@linux-foundation.org: convert remaining __FUNCTION__ references]
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Revert commit f252cb09e1 (ACPI / EC: Add query flushing support),
because it breaks system suspend on Acer Aspire S5. The machine
just hangs solid at the last stage of suspend (after taking non-boot
CPUs offline).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Revert commit b5bca896ef (ACPI / EC: Add GPE reference counting
debugging messages), because it depends on commit f252cb09e1
(ACPI / EC: Add query flushing support) which breaks system suspend
on Acer Aspire S5 and needs to be reverted.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull networking updates from David Miller:
1) More iov_iter conversion work from Al Viro.
[ The "crypto: switch af_alg_make_sg() to iov_iter" commit was
wrong, and this pull actually adds an extra commit on top of the
branch I'm pulling to fix that up, so that the pre-merge state is
ok. - Linus ]
2) Various optimizations to the ipv4 forwarding information base trie
lookup implementation. From Alexander Duyck.
3) Remove sock_iocb altogether, from CHristoph Hellwig.
4) Allow congestion control algorithm selection via routing metrics.
From Daniel Borkmann.
5) Make ipv4 uncached route list per-cpu, from Eric Dumazet.
6) Handle rfs hash collisions more gracefully, also from Eric Dumazet.
7) Add xmit_more support to r8169, e1000, and e1000e drivers. From
Florian Westphal.
8) Transparent Ethernet Bridging support for GRO, from Jesse Gross.
9) Add BPF packet actions to packet scheduler, from Jiri Pirko.
10) Add support for uniqu flow IDs to openvswitch, from Joe Stringer.
11) New NetCP ethernet driver, from Muralidharan Karicheri and Wingman
Kwok.
12) More sanely handle out-of-window dupacks, which can result in
serious ACK storms. From Neal Cardwell.
13) Various rhashtable bug fixes and enhancements, from Herbert Xu,
Patrick McHardy, and Thomas Graf.
14) Support xmit_more in be2net, from Sathya Perla.
15) Group Policy extensions for vxlan, from Thomas Graf.
16) Remove Checksum Offload support for vxlan, from Tom Herbert.
17) Like ipv4, support lockless transmit over ipv6 UDP sockets. From
Vlad Yasevich.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1494+1 commits)
crypto: fix af_alg_make_sg() conversion to iov_iter
ipv4: Namespecify TCP PMTU mechanism
i40e: Fix for stats init function call in Rx setup
tcp: don't include Fast Open option in SYN-ACK on pure SYN-data
openvswitch: Only set TUNNEL_VXLAN_OPT if VXLAN-GBP metadata is set
ipv6: Make __ipv6_select_ident static
ipv6: Fix fragment id assignment on LE arches.
bridge: Fix inability to add non-vlan fdb entry
net: Mellanox: Delete unnecessary checks before the function call "vunmap"
cxgb4: Add support in cxgb4 to get expansion rom version via ethtool
ethtool: rename reserved1 memeber in ethtool_drvinfo for expansion ROM version
net: dsa: Remove redundant phy_attach()
IB/mlx4: Reset flow support for IB kernel ULPs
IB/mlx4: Always use the correct port for mirrored multicast attachments
net/bonding: Fix potential bad memory access during bonding events
tipc: remove tipc_snprintf
tipc: nl compat add noop and remove legacy nl framework
tipc: convert legacy nl stats show to nl compat
tipc: convert legacy nl net id get to nl compat
tipc: convert legacy nl net id set to nl compat
...
- Rework of the core ACPI resources parsing code to fix issues
in it and make using resource offsets more convenient and
consolidation of some resource-handing code in a couple of places
that have grown analagous data structures and code to cover the
the same gap in the core (Jiang Liu, Thomas Gleixner, Lv Zheng).
- ACPI-based IOAPIC hotplug support on top of the resources handling
rework (Jiang Liu, Yinghai Lu).
- ACPICA update to upstream release 20150204 including an interrupt
handling rework that allows drivers to install raw handlers for
ACPI GPEs which then become entirely responsible for the given GPE
and the ACPICA core code won't touch it (Lv Zheng, David E Box,
Octavian Purdila).
- ACPI EC driver rework to fix several concurrency issues and other
problems related to events handling on top of the ACPICA's new
support for raw GPE handlers (Lv Zheng).
- New ACPI driver for AMD SoCs analogous to the LPSS (Low-Power
Subsystem) driver for Intel chips (Ken Xue).
- Two minor fixes of the ACPI LPSS driver (Heikki Krogerus,
Jarkko Nikula).
- Two new blacklist entries for machines (Samsung 730U3E/740U3E and
510R) where the native backlight interface doesn't work correctly
while the ACPI one does (Hans de Goede).
- Rework of the ACPI processor driver's handling of idle states
to make the code more straightforward and less bloated overall
(Rafael J Wysocki).
- Assorted minor fixes related to ACPI and SFI (Andreas Ruprecht,
Andy Shevchenko, Hanjun Guo, Jan Beulich, Rafael J Wysocki,
Yaowei Bai).
- PCI core power management modification to avoid resuming (some)
runtime-suspended devices during system suspend if they are in
the right states already (Rafael J Wysocki).
- New SFI-based cpufreq driver for Intel platforms using SFI
(Srinidhi Kasagar).
- cpufreq core fixes, cleanups and simplifications (Viresh Kumar,
Doug Anderson, Wolfram Sang).
- SkyLake CPU support and other updates for the intel_pstate driver
(Kristen Carlson Accardi, Srinivas Pandruvada).
- cpufreq-dt driver cleanup (Markus Elfring).
- Init fix for the ARM big.LITTLE cpuidle driver (Sudeep Holla).
- Generic power domains core code fixes and cleanups (Ulf Hansson).
- Operating Performance Points (OPP) core code cleanups and kernel
documentation update (Nishanth Menon).
- New dabugfs interface to make the list of PM QoS constraints
available to user space (Nishanth Menon).
- New devfreq driver for Tegra Activity Monitor (Tomeu Vizoso).
- New devfreq class (devfreq_event) to provide raw utilization data
to devfreq governors (Chanwoo Choi).
- Assorted minor fixes and cleanups related to power management
(Andreas Ruprecht, Krzysztof Kozlowski, Rickard Strandqvist,
Pavel Machek, Todd E Brandt, Wonhong Kwon).
- turbostat updates (Len Brown) and cpupower Makefile improvement
(Sriram Raghunathan).
/
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Merge tag 'pm+acpi-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI and power management updates from Rafael Wysocki:
"We have a few new features this time, including a new SFI-based
cpufreq driver, a new devfreq driver for Tegra Activity Monitor, a new
devfreq class for providing its governors with raw utilization data
and a new ACPI driver for AMD SoCs.
Still, the majority of changes here are reworks of existing code to
make it more straightforward or to prepare it for implementing new
features on top of it. The primary example is the rework of ACPI
resources handling from Jiang Liu, Thomas Gleixner and Lv Zheng with
support for IOAPIC hotplug implemented on top of it, but there is
quite a number of changes of this kind in the cpufreq core, ACPICA,
ACPI EC driver, ACPI processor driver and the generic power domains
core code too.
The most active developer is Viresh Kumar with his cpufreq changes.
Specifics:
- Rework of the core ACPI resources parsing code to fix issues in it
and make using resource offsets more convenient and consolidation
of some resource-handing code in a couple of places that have grown
analagous data structures and code to cover the the same gap in the
core (Jiang Liu, Thomas Gleixner, Lv Zheng).
- ACPI-based IOAPIC hotplug support on top of the resources handling
rework (Jiang Liu, Yinghai Lu).
- ACPICA update to upstream release 20150204 including an interrupt
handling rework that allows drivers to install raw handlers for
ACPI GPEs which then become entirely responsible for the given GPE
and the ACPICA core code won't touch it (Lv Zheng, David E Box,
Octavian Purdila).
- ACPI EC driver rework to fix several concurrency issues and other
problems related to events handling on top of the ACPICA's new
support for raw GPE handlers (Lv Zheng).
- New ACPI driver for AMD SoCs analogous to the LPSS (Low-Power
Subsystem) driver for Intel chips (Ken Xue).
- Two minor fixes of the ACPI LPSS driver (Heikki Krogerus, Jarkko
Nikula).
- Two new blacklist entries for machines (Samsung 730U3E/740U3E and
510R) where the native backlight interface doesn't work correctly
while the ACPI one does (Hans de Goede).
- Rework of the ACPI processor driver's handling of idle states to
make the code more straightforward and less bloated overall (Rafael
J Wysocki).
- Assorted minor fixes related to ACPI and SFI (Andreas Ruprecht,
Andy Shevchenko, Hanjun Guo, Jan Beulich, Rafael J Wysocki, Yaowei
Bai).
- PCI core power management modification to avoid resuming (some)
runtime-suspended devices during system suspend if they are in the
right states already (Rafael J Wysocki).
- New SFI-based cpufreq driver for Intel platforms using SFI
(Srinidhi Kasagar).
- cpufreq core fixes, cleanups and simplifications (Viresh Kumar,
Doug Anderson, Wolfram Sang).
- SkyLake CPU support and other updates for the intel_pstate driver
(Kristen Carlson Accardi, Srinivas Pandruvada).
- cpufreq-dt driver cleanup (Markus Elfring).
- Init fix for the ARM big.LITTLE cpuidle driver (Sudeep Holla).
- Generic power domains core code fixes and cleanups (Ulf Hansson).
- Operating Performance Points (OPP) core code cleanups and kernel
documentation update (Nishanth Menon).
- New dabugfs interface to make the list of PM QoS constraints
available to user space (Nishanth Menon).
- New devfreq driver for Tegra Activity Monitor (Tomeu Vizoso).
- New devfreq class (devfreq_event) to provide raw utilization data
to devfreq governors (Chanwoo Choi).
- Assorted minor fixes and cleanups related to power management
(Andreas Ruprecht, Krzysztof Kozlowski, Rickard Strandqvist, Pavel
Machek, Todd E Brandt, Wonhong Kwon).
- turbostat updates (Len Brown) and cpupower Makefile improvement
(Sriram Raghunathan)"
* tag 'pm+acpi-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (151 commits)
tools/power turbostat: relax dependency on APERF_MSR
tools/power turbostat: relax dependency on invariant TSC
Merge branch 'pci/host-generic' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci into acpi-resources
tools/power turbostat: decode MSR_*_PERF_LIMIT_REASONS
tools/power turbostat: relax dependency on root permission
ACPI / video: Add disable_native_backlight quirk for Samsung 510R
ACPI / PM: Remove unneeded nested #ifdef
USB / PM: Remove unneeded #ifdef and associated dead code
intel_pstate: provide option to only use intel_pstate with HWP
ACPI / EC: Add GPE reference counting debugging messages
ACPI / EC: Add query flushing support
ACPI / EC: Refine command storm prevention support
ACPI / EC: Add command flushing support.
ACPI / EC: Introduce STARTED/STOPPED flags to replace BLOCKED flag
ACPI: add AMD ACPI2Platform device support for x86 system
ACPI / table: remove duplicate NULL check for the handler of acpi_table_parse()
ACPI / EC: Update revision due to raw handler mode.
ACPI / EC: Reduce ec_poll() by referencing the last register access timestamp.
ACPI / EC: Fix several GPE handling issues by deploying ACPI_GPE_DISPATCH_RAW_HANDLER mode.
ACPICA: Events: Enable APIs to allow interrupt/polling adaptive request based GPE handling model
...
* acpi-resources: (23 commits)
Merge branch 'pci/host-generic' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci into acpi-resources
x86/irq, ACPI: Implement ACPI driver to support IOAPIC hotplug
ACPI: Add interfaces to parse IOAPIC ID for IOAPIC hotplug
x86/PCI: Refine the way to release PCI IRQ resources
x86/PCI/ACPI: Use common ACPI resource interfaces to simplify implementation
x86/PCI: Fix the range check for IO resources
PCI: Use common resource list management code instead of private implementation
resources: Move struct resource_list_entry from ACPI into resource core
ACPI: Introduce helper function acpi_dev_filter_resource_type()
ACPI: Add field offset to struct resource_list_entry
ACPI: Translate resource into master side address for bridge window resources
ACPI: Return translation offset when parsing ACPI address space resources
ACPI: Enforce stricter checks for address space descriptors
ACPI: Set flag IORESOURCE_UNSET for unassigned resources
ACPI: Normalize return value of resource parser functions
ACPI: Fix a bug in parsing ACPI Memory24 resource
ACPI: Add prefetch decoding to the address space parser
ACPI: Move the window flag logic to the combined parser
ACPI: Unify the parsing of address_space and ext_address_space
ACPI: Let the parser return false for disabled resources
...
* acpi-processor:
ACPI / cpuidle: Common callback routine for entering states
ACPI / cpuidle: Merge acpi_idle_enter_c1() and acpi_idle_enter_simple()
ACPI / cpuidle: Drop flags.bm_check tests from acpi_idle_enter_bm()
ACPI / cpuidle: Clean up white space in a switch statement
ACPI / cpuidle: Drop irrelevant comment from acpi_idle_enter_simple()
ACPI / cpuidle: Clean up fallback to C1 checks
ACPI / cpuidle: Drop unnecessary calls from ->enter callback routines
ACPI / cpuidle: Drop unnecessary calls from acpi_idle_do_entry()
* acpi-doc:
MAINTAINERS / ACPI: add the necessary '/' according to entry rules
ACPI / Documentation: add a missing '='
* acpi-pm:
ACPI / sleep: mark acpi_sleep_dmi_check() __init
* acpi-pcc:
ACPI / PCC: Use pr_debug() for debug messages in pcc_init()
* acpi-tables:
ACPI / table: remove duplicate NULL check for the handler of acpi_table_parse()
* acpi-video:
ACPI / video: Add disable_native_backlight quirk for Samsung 510R
ACPI / video: Add disable_native_backlight quirk for Samsung 730U3E/740U3E
* acpi-soc:
ACPI: add AMD ACPI2Platform device support for x86 system
ACPI / LPSS: Remove non-existing clock control from Intel Lynxpoint I2C
ACPI / LPSS: check the result of ioremap()
* acpica:
ACPICA: Events: Enable APIs to allow interrupt/polling adaptive request based GPE handling model
ACPICA: Events: Introduce acpi_set_gpe()/acpi_finish_gpe() to reduce divergences
ACPICA: Events: Introduce ACPI_GPE_DISPATCH_RAW_HANDLER to fix 2 issues for the current GPE APIs
ACPICA: Update version to 20150204
ACPICA: Update Copyright headers to 2015
ACPICA: Hardware: Cast GPE enable_mask before storing
ACPICA: Events: Cleanup GPE dispatcher type obtaining code
ACPICA: Events: Cleanup to move acpi_gbl_global_event_handler invocation out of acpi_ev_gpe_dispatch()
ACPICA: Events: Cleanup of resetting the GPE handler to NULL before removing
ACPICA: Events: Fix uninitialized variable
ACPICA: Events: Remove acpi_ev_valid_gpe_event() due to current restriction
ACPICA: Events: Remove duplicated sanity check in acpi_ev_enable_gpe()
ACPICA: Events: Back port "ACPICA: Save current masks of enabled GPEs after enable register writes"
ACPICA: Resources: Provide common part for struct acpi_resource_address structures.
ACPI: Introduce acpi_unload_parent_table() usages in Linux kernel
ACPICA: take ACPI_MTX_INTERPRETER in acpi_unload_table_id()
Backlight control through the native intel interface does not work properly
on the Samsung 510R, where as using the acpi_video interface does work, add
a quirk for this.
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1186097
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In commit 5de21bb998 ("ACPI / PM: Drop CONFIG_PM_RUNTIME from the
ACPI core"), all occurrences of CONFIG_PM_RUNTIME were replaced with
CONFIG_PM. This created the following structure of #ifdef blocks in
the code:
[...]
#ifdef CONFIG_PM
#ifdef CONFIG_PM
/* always on / undead */
#ifdef CONFIG_PM_SLEEP
[...]
#endif
#endif
[...]
#endif
This patch removes the inner "#ifdef CONFIG_PM" block as it will
always be enabled when the outer block is enabled. This inconsistency
was found using the undertaker-checkpatch tool.
Signed-off-by: Andreas Ruprecht <rupran@einserver.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch enhances debugging with the GPE reference count messages added.
No functional changes.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch implementes the QR_EC flushing support.
Grace periods are implemented from the detection of an SCI_EVT to the
submission/completion of the QR_EC transaction. During this period, all
EC command transactions are allowed to be submitted.
Note that query periods and event periods are intentionally distiguished to
allow further improvements.
1. Query period: from the detection of an SCI_EVT to the sumission of the
QR_EC command. This period is used for storming prevention, as currently
QR_EC is deferred to a work queue rather than directly issued from the
IRQ context even there is no other transactions pending, so malicous
SCI_EVT GPE can act like "level triggered" to trigger a GPE storm. We
need to be prepared for this. And in the future, we may change it to be
a part of the advance_transaction() where we will try QR_EC submission
in appropriate positions to avoid such GPE storming.
2. Event period: from the detection of an SCI_EVT to the completion of the
QR_EC command. We may extend it to the completion of _Qxx evaluation.
This is actually a grace period for event flushing, but we only flush
queries due to the reason stated in known issue 1. That's also why we
use EC_FLAGS_EVENT_xxx. During this period, QR_EC transactions need to
pass the flushable submission check.
In this patch, the following flags are implemented:
1. EC_FLAGS_EVENT_ENABLED: this is derived from the old
EC_FLAGS_QUERY_PENDING flag which can block SCI_EVT handlings.
With this flag, the logics implemented by the original flag are
extended:
1. Old logic: unless both of the flags are set, the event poller will
not be scheduled, and
2. New logic: as soon as both of the flags are set, the evet poller will
be scheduled.
2. EC_FLAGS_EVENT_DETECTED: this is also derived from the old
EC_FLAGS_QUERY_PENDING flag which can block SCI_EVT detection. It thus
can be used to indicate the storming prevention period for query
submission.
acpi_ec_submit_request()/acpi_ec_complete_request() are invoked to
implement this period so that acpi_set_gpe() can be invoked under the
"reference count > 0" condition.
3. EC_FLAGS_EVENT_PENDING: this is newly added to indicate the grace period
for event flushing (query flushing for now).
acpi_ec_submit_request()/acpi_ec_complete_request() are invoked to
implement this period so that the flushing process can wait until the
event handling (query transaction for now) to be completed.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=82611
Link: https://bugzilla.kernel.org/show_bug.cgi?id=77431
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Tested-by: Ortwin Glück <odi@odi.ch>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch refines EC command storm prevention support.
Current command storming code is wrong, when the storming condition is
detected, it only flags the condition without doing anything for the
current command but performing storming prevention for the follow-up
commands. So:
1. The first command which suffers from the storming still suffers from
storming.
2. The follow-up commands which may not suffer from the storming are
unconditionally forced into the storming prevention mode.
Ideally, we should only enable storm prevention immediately after detection
for the current command so that the next command can try the
power/performance efficient interrupt mode again.
This patch improves the command storm prevention by disabling GPE right
after the detection and re-enabling it right before completing the command
transaction using the GPE storming prevention APIs. This thus deploys the
following GPE handling model:
1. acpi_enable_gpe()/acpi_disable_gpe() for reference count changes:
This set of APIs are used for EC usage reference counting.
2. acpi_set_gpe(ACPI_GPE_ENABLE)/acpi_set_gpe(ACPI_GPE_DISABLE):
This set of APIs are used for preventing GPE storm. They must be invoked
when the reference count > 0.
Note that as the storming prevention should always happen when there is
an outstanding request, or GPE enabling value will be messed up by the
races. This patch also adds BUG_ON() to enforces this rule to prevent
future bugs.
The msleep(1) used after completing a transaction is useless now as this
sounds like a guard time only useful for platforms that need the
EC_FLAGS_MSI quirks while we have fixed GPE race issues using the previous
raw handler mode enabling. It is kept to avoid regressions. A seperate
patch which deletes EC_FLAGS_MSI quirks should take care of deleting it.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch implements the EC command flushing support.
During the grace period indicated by EC_FLAGS_STARTED and EC_FLAGS_STOPPED,
all submitted EC command transactions can be completed and new submissions
are prevented before suspending so that the EC hardware can be ensured to
be in the idle state when the system is resumed.
There is a good indicator for flush support:
All acpi_ec_submit_request() is invoked after checking driver state with
acpi_ec_started() except the first one. This means all code paths can be
flushed as fast as possible by discarding the requests occurred after the
flush operation. The reference increased for such kind of code path is
wrapped by acpi_ec_submit_flushable_request().
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Tested-by: Ortwin Glück <odi@odi.ch>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
By using the 2 flags, we can indicate an inter-mediate state where the
current transactions should be completed while the new transactions should
be dropped.
The comparison of the old flag and the new flags:
Old New
about to set BLOCKED STOPPED set / STARTED set
BLOCKED set STOPPED clear / STARTED clear
BLOCKED clear STOPPED clear / STARTED set
A new period can be indicated by the 2 flags. The new period is between the
point where we are about to set BLOCKED and the point when the BLOCKED is
set. The new flags facilitate us with acpi_ec_started() check to allow the
EC transaction to be submitted during the new period. This period thus can
be used as a grace period for the EC transaction flushing.
The only functional change after applying this patch is:
1. The GPE enabling/disabling is protected by the EC specific lock. We can
do this because of recent ACPICA GPE API enhancement. This is reasonable
as the GPE disabling/enabling state should only be determined by the EC
driver's state machine which is protected by the EC spinlock.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Tested-by: Ortwin Glück <odi@odi.ch>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This new feature is to interpret AMD specific ACPI device to
platform device such as I2C, UART, GPIO found on AMD CZ and
later chipsets. It based on example intel LPSS. Now, it can
support AMD I2C, UART and GPIO.
Signed-off-by: Ken Xue <Ken.Xue@amd.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In acpi_table_parse(), pointer of the table to pass to handler() is
checked before handler() called, so remove all the duplicate NULL
check in the handler function.
CC: Tony Luck <tony.luck@intel.com>
CC: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Conflicts:
drivers/net/vxlan.c
drivers/vhost/net.c
include/linux/if_vlan.h
net/core/dev.c
The net/core/dev.c conflict was the overlap of one commit marking an
existing function static whilst another was adding a new function.
In the include/linux/if_vlan.h case, the type used for a local
variable was changed in 'net', whereas the function got rewritten
to fix a stacked vlan bug in 'net-next'.
In drivers/vhost/net.c, Al Viro's iov_iter conversions in 'net-next'
overlapped with an endainness fix for VHOST 1.0 in 'net'.
In drivers/net/vxlan.c, vxlan_find_vni() added a 'flags' parameter
in 'net-next' whereas in 'net' there was a bug fix to pass in the
correct network namespace pointer in calls to this function.
Signed-off-by: David S. Miller <davem@davemloft.net>
The bug fixes around GPE races have been done to the EC driver by the
previous commits. This patch increases the revision to 3 to indicate the
behavior differences between the old and the new drivers. The
copyright/authorship notices are also updated.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Timeout in the ec_poll() doesn't refer to the last register access time. It
thus can win the competition against the acpi_ec_gpe_handler() if a
transaction takes longer than 1ms but individual register accesses are less
than 1ms. In some cases, it can make the following silicon bug easier to
be triggered:
GPE EN is not wired to the GPE trigger line, so when GPE STS is already
set when 1 is written to GPE EN, no GPE can be triggered.
This patch adds register access timestamp reference support for ec_poll()
to reduce the number of ec_poll() invocations.
Reported-by: Venkat Raghavulu <venkat.raghavulu@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch switches EC driver into ACPI_GPE_DISPATCH_RAW_HANDLER mode where
the GPE lock is not held for acpi_ec_gpe_handler() and the ACPICA internal
GPE enabling/disabling/clearing operations are bypassed so that further
improvements are possible with the GPE APIs.
There are 2 strong reasons for deploying raw GPE handler mode in the EC
driver:
1. Some hardware logics can control their interrupts via their own
registers, so their interrupts can be disabled/enabled/acknowledged
without using the super IRQ controller provided functions. While there
is no mean (EC commands) for the EC driver to achieve this.
2. During suspending, the EC driver is still working for a while to
complete the platform firmware provided functionailities using ec_poll()
after all GPEs are disabled (see acpi_ec_block_transactions()), which
means the EC driver will drive the EC GPE out of the GPE core's control.
Without deploying the raw GPE handler mode, we can see many races between
the EC driver and the GPE core due to the above restrictions:
1. There is a race condition due to ACPICA internal GPE
disabling/clearing/enabling logics in acpi_ev_gpe_dispatch():
Orignally EC GPE is disabled (EN=0), cleared (STS=0) before invoking a
GPE handler and re-enabled (EN=1) after invoking a GPE handler in
acpi_ev_gpe_dispatch(). When re-enabling appears, GPE may be flagged
(STS=1).
=================================================================
(event pending A)
=================================================================
acpi_ev_gpe_dispatch() ec_poll()
EN=0
STS=0
acpi_ec_gpe_handler()
*****************************************************************
(event handling A)
Lock(EC)
advance_transaction()
EC_SC read
=================================================================
(event pending B)
=================================================================
EC_SC handled
Unlock(EC)
*****************************************************************
*****************************************************************
(event handling B)
Lock(EC)
advance_transaction()
EC_SC read
=================================================================
(event pending C)
=================================================================
EC_SC handled
Unlock(EC)
*****************************************************************
EN=1
This race condition is the root cause of different issues on different
silicon variations.
A. Silicon variation A:
On some platforms, GPE will be triggered due to "writing 1 to EN when
STS=1". This is because both EN and STS lines are wired to the GPE
trigger line.
1. Issue 1:
We can see no-op acpi_ec_gpe_handler() invoked on such platforms.
This is because:
a. event pending B: An event can arrive after ACPICA's GPE
clearing performed in acpi_ev_gpe_dispatch(), this event may
fail to be detected by EC_SC read that is performed before its
arrival;
b. event handling B: The event can be handled in ec_poll() because
EC lock is released after acpi_ec_gpe_handler() invocation;
c. There is no code in ec_poll() to clear STS but the GPE can
still be triggered by the EN=1 write performed in
acpi_ev_finish_gpe(), this leads to a no-op EC GPE handler
invocation;
d. As no-op GPE handler invocations are counted by the EC driver
to trigger the command storming conditions, the wrong no-op
GPE handler invocations thus can easily trigger wrong command
storming conditions.
Note 1:
If we removed GPE disabling/enabling code from
acpi_ev_gpe_dispatch(), we could still see no-op GPE handlers
triggered by the event arriving after the GPE clearing and before
the GPE handling on both silicon variation A and B. This can only
occur if the CPU is very slow (timing slice between STS=0 write
and EC_SC read should be short enough before hardware sets another
GPE indication). Thus this is very rare and is not what we need to
fix.
B. Silicon variation B:
On other platforms, GPE may not be triggered due to "writing 1 to EN
when STS=1". This is because only STS line is wired to the GPE
trigger line.
2. Issue 2:
We can see GPE loss on such platforms. This is because:
a. event pending B vs. event handling A: An event can arrive after
ACPICA's GPE handling performed in acpi_ev_gpe_dispatch(), or
event pending C vs. event handling B: An event can arrive after
Linux's GPE handling performed in ec_poll(),
these events may fail to be detected by EC_SC read that is
performed before their arrival;
b. The GPE cannot be triggered by EN=1 write performed in
acpi_ev_finish_gpe();
c. If no polling mechanism is implemented in the driver for the
pending event (for example, SCI_EVT), this event is lost due to
no GPE being triggered.
Note 2:
On most platforms, there might be another rule that GPE may not be
triggered due to "writing 1 to STS when STS=1 and EN=1".
Then on silicon variation B, an even worse case is if the issue 2
event loss happens, further events may never trigger GPE again on
such platforms due to being blocked by the current STS=1. Unless
someone clears STS, all events have to be polled.
2. There is a race condition due to lacking in GPE status checking in EC
driver:
Originally, GPE status is checked in ACPICA core but not checked in
the GPE handler. Thus since the status checking and handling is not
locked, it can be interrupted by another handling path.
=================================================================
(event pending A)
=================================================================
acpi_ev_gpe_detect() ec_poll()
if (EN==1 && STS==1)
*****************************************************************
(event handling A)
Lock(EC)
advance_transaction()
EC_SC read
EC_SC handled
Unlock(EC)
*****************************************************************
acpi_ev_gpe_dispatch()
EN=0
STS=0
acpi_ec_gpe_handler()
*****************************************************************
(event handling B)
Lock(EC)
advance_transaction()
EC_SC read
Unlock(EC)
*****************************************************************
3. Issue 3:
We can see no-op acpi_ec_gpe_handler() invoked on both silicon
variation A and B. This is because:
a. event pending A: An event can arrive to trigger an EC GPE and
ACPICA checks it and is about to invoke the EC GPE handler;
b. event handling A: The event can be handled in ec_poll() because
EC lock is not held after the GPE status checking;
c. event handling B: Then when the EC GPE handler is invoked, it
becomes a no-op GPE handler invocation.
d. As no-op GPE handler invocations are counted by the EC driver
to trigger the command storming conditions, the wrong no-op
GPE handler invocations thus can easily trigger wrong command
storming conditions.
Note 3:
This no-op GPE handler invocation is rare because the time between
the IRQ arrival and the acpi_ec_gpe_handler() invocation is less than
the timeout value waited in ec_poll(). So most of the no-op GPE
handler invocations are caused by the reason described in issue 1.
3. There is a race condition due to ACPICA internal GPE clearing logic in
acpi_enable_gpe():
During runtime, acpi_enable_gpe() can be invoked by the EC storming
prevention code. When it is invoked, GPE may be flagged (STS=1).
=================================================================
(event pending A)
=================================================================
acpi_ev_gpe_dispatch() acpi_ec_transaction()
EN=0
STS=0
acpi_ec_gpe_handler()
*****************************************************************
(event handling A)
Lock(EC)
advance_transaction()
EC_SC read
EC_SC handled
Unlock(EC)
*****************************************************************
EN=1 ?
Lock(EC)
Unlock(EC)
=================================================================
(event pending B)
=================================================================
acpi_enable_gpe()
STS=0
EN=1
4. Issue 4:
We can see GPE loss on both silicon variation A and B platforms.
This is because:
a. event pending B: An event can arrive right before ACPICA's GPE
clearing performed in acpi_enable_gpe();
b. If the GPE is cleared when GPE is disabled, then EN=1 write in
acpi_enable_gpe() cannot trigger this GPE;
c. If no polling mechanism is implemented in the driver for this
event (for example, SCI_EVT), this event is lost due to no GPE
being triggered.
Note 4:
Currently we don't have this issue, but after we switch the EC
driver into ACPI_GPE_DISPATCH_RAW_HANDLER mode, we need to take care
of handling this because the EN=1 write in acpi_ev_gpe_dispatch()
will be abandoned.
There might be more race issues for the current GPE handler usages. This is
because the EC IRQ's enabling/disabling/checking/clearing/handling
operations should be locked by a single lock that is under the EC driver's
control to achieve the serialization. Which means we need to invoke GPE
APIs with EC driver's lock held and all ACPICA internal GPE operations
related to the GPE handler should be abandoned. Invoking GPE APIs inside of
the EC driver lock and bypassing ACPICA internal GPE operations requires
the ACPI_GPE_DISPATCH_RAW_HANDLER mode where the same lock used by the APIs
are released prior than invoking the handlers. Otherwise, we can see dead
locks due to circular locking dependencies (see Reference below).
This patch then switches the EC driver into the
ACPI_GPE_DISPATCH_RAW_HANDLER mode so that it can perform correct GPE
operations using the GPE APIs:
1. Bypasses EN modifications performed in acpi_ev_gpe_dispatch() by
using acpi_install_gpe_raw_handler() and invoking all GPE APIs with EC
spin lock held. This can fix issue 1 as it makes a non frequent GPE
enabling/disabling environment.
2. Bypasses STS clearing performed in acpi_enable_gpe() by replacing
acpi_enable_gpe()/acpi_disable_gpe() with acpi_set_gpe(). This can fix
issue 4. And this can also help to fix issue 1 as it makes a no sudden
GPE clearing environment when GPE is frequently enabled/disabled.
3. Ensures STS acknowledged before handling by invoking acpi_clear_gpe()
in advance_transaction(). This can finally fix issue 1 even in a
frequent GPE enabling/disabling environment. And this can also finally
fix issue 3 when issue 2 is fixed.
Note 3:
GPE clearing is edge triggered W1C, which means we can clear it right
before handling it. Since all EC GPE indications are handled in
advance_transaction() by previous commits, we can now move GPE clearing
into it to implement the correct GPE clearing.
Note 4:
We can use acpi_set_gpe() which is not shared GPE safer instead of
acpi_enable_gpe()/acpi_disable_gpe() because EC GPE is not shared by
other hardware, which is mentioned in the ACPI specification 5.0, 12.6
Interrupt Model: "OSPM driver treats this as an edge event (the EC SCI
cannot be shared)". So we can stop using shared GPE safer APIs
acpi_enable_gpe()/acpi_disable_gpe() in the EC driver. Otherwise
cleanups need to be made in acpi_ev_enable_gpe() to bypass the GPE
clearing logic before keeping acpi_enable_gpe().
This patch also invokes advance_transaction() when GPE is re-enabled in the
task context which:
1. Ensures EN=1 can trigger GPE by checking and handling EC status register
right after EN=1 writes. This can fix issue 2.
After applying this patch, without frequent GPE enablings considered:
=================================================================
(event pending A)
=================================================================
acpi_ec_gpe_handler() ec_poll()
*****************************************************************
(event handling A)
Lock(EC)
advance_transaction()
if STS==1
STS=0
EC_SC read
=================================================================
(event pending B)
=================================================================
EC_SC handled
Unlock(EC)
*****************************************************************
*****************************************************************
(event handling B)
Lock(EC)
advance_transaction()
if STS==1
STS=0
EC_SC read
=================================================================
(event pending C)
=================================================================
EC_SC handled
Unlock(EC)
*****************************************************************
The event pending for issue 1 (event pending B) can arrive as a next GPE
due to the previous IRQ context STS=0 write. And if it is handled by
ec_poll() (event handling B), as it is also acknowledged by ec_poll(), the
event pending for issue 2 (event pending C) can properly arrive as a next
GPE after the task context STS=0 write. So no GPE will be lost and never
triggered due to GPE clearing performed in the wrong position. And since
all GPE handling is performed after a locked GPE status checking, we can
hardly see no-op GPE handler invocations due to issue 1 and 3. We may still
see no-op GPE handler invocations due to "Note 1", but as it is inevitable,
it needn't be fixed.
After applying this patch, with frequent GPE enablings considered:
=================================================================
(event pending A)
=================================================================
acpi_ec_gpe_handler() acpi_ec_transaction()
*****************************************************************
(event handling A)
Lock(EC)
advance_transaction()
if STS==1
STS=0
EC_SC read
=================================================================
(event pending B)
=================================================================
EC_SC handled
Unlock(EC)
*****************************************************************
*****************************************************************
(event handling B)
Lock(EC)
EN=1
if STS==1
advance_transaction()
if STS==1
STS=0
EC_SC read
=================================================================
(event pending C)
=================================================================
EC_SC handled
Unlock(EC)
*****************************************************************
The event pending for issue 2 can be manually handled by
advance_transaction(). And after the STS=0 write performed in the manual
triggered advance_transaction(), GPE can always arrive. So no GPE will be
lost due to frequent GPE disabling/enabling performed in the driver like
issue 4.
Note 5:
It's ideally when EN=1 write occurred, an IRQ thread should be woken up to
handle the GPE when the GPE was raised. But this requires the IRQ thread to
contain the poller code for all EC GPE indications, while currently some of
the indications are handled in the user tasks. It then is very hard for the
code to determine whether a user task should be invoked or the poller work
item should be scheduled. So we have to invoke advance_transaction()
directly now and it leaves us such a restriction for the GPE re-enabling:
it must be performed in the task context to avoid starving the GPEs.
As a conclusion: we can see the EC GPE is always handled in serial after
deploying the raw GPE handler mode:
Lock(EC)
if (STS==1)
STS=0
EC_SC read
EC_SC handled
Unlock(EC)
The EC driver specific lock is responsible to make the EC GPE handling
processes serialized so that EC can handle its GPE from both IRQ and task
contexts and the next IRQ can be ensured to arrive after this process.
Note 6:
We have many EC_FLAGS_MSI qurik users in the current driver. They all seem
to be suffering from unexpected GPE triggering source lost. And they are
false root caused to a timing issue. Since EC communication protocol has
already flow control defined, timing shouldn't be the root cause, while
this fix might be fixing the root cause of the old bugs.
Link: https://lkml.org/lkml/2014/11/4/974
Link: https://lkml.org/lkml/2014/11/18/316
Link: https://www.spinics.net/lists/linux-acpi/msg54340.html
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPICA commit da9a83e1a845f2d7332bdbc0632466b2595e5424
For acpi_set_gpe()/acpi_enable_gpe(), our target is to purify them to be APIs
that can be used for various GPE handling models, so we need them to be
pure GPE enabling APIs. GPE enabling/disabling has 2 use cases:
1. Driver may permanently enable/disable GPEs according to the usage
counts.
1. When upper layers (the users of the driver) submit requests to the
driver, it means they care about the underlying hardware. GPE need
to be enabled for the first request submission and disabled for the
last request completion.
2. When the GPE is shared between 2+ silicon logics. GPE need to be
enabled for either silicon logic's driver and disabled when all of
the drivers are not started.
For these cases, acpi_enable_gpe()/acpi_disable_gpe() should be used. When
the usage count is increased from 0 to 1, the GPE is enabled and it is
disabled when the usage count is decrased from 1 to 0.
2. Driver may temporarily disables the GPE to enter an GPE polling mode and
wants to re-enable it later.
1. Prevent GPE storming: when a driver cannot fully solve the condition
that triggered the GPE in the GPE context, in order not to trigger
GPE storm, driver has to disable GPE to switch into the polling mode
and re-enables it in the non interrupt context after the storming
condition is cleared.
2. Meet throughput requirement: some IO drivers need to poll hardware
again and again until nothing indicated instead of just handling once
for one interruption, this need to be done in the polling mode or the
IO flood may prevent the GPE handler from returning.
3. Meet realtime requirement: in order not to block CPU to handle higher
realtime prioritized GPEs, lower priority GPEs can be handled in the
polling mode.
For these cases, acpi_set_gpe() should be used to switch to/from the
polling mode.
This patch adds unconditional GPE enabling support into acpi_set_gpe() so
that this API can be used by the drivers to switch back from the GPE
polling mode unconditionally.
Originally this function includes GPE clearing logic in it.
First, the GPE clearing is typically used in the GPE handling code to:
1. Acknowledge the GPE when we know there is an edge triggered GPE raised
and is about to handle it, otherwise the unexpected clearing may lead to
a GPE loss;
2. Issue actions after we have handled a level triggered GPE, otherwise
the unexpected clearing may trigger unwanted OSPM actions to the
hardware (for example, clocking in out-dated write FIFO data).
Thus the GPE clearing is not suitable to be used in the GPE enabling APIs.
Second, the combination of acknowledging and enabling may also not be
expected by the hardware drivers. For GPE clearing, we have a seperate API
acpi_clear_gpe(). There are cases drivers do want the 2 operations to be
split. So splitting these 2 operations could facilitates drivers the
maximum possibilities to achieve success. For a combined one, we already
have acpi_finish_gpe() ready to be invoked.
Given the fact that drivers should complete all outstanding requests before
putting themselves into the sleep states, as this API is executed for
outstanding requests, it should also have nothing to do with the
"RUN"/"WAKE" distinguishing. That's why the acpi_set_gpe(ACPI_GPE_ENABLE)
should not be implemented by acpi_hw_low_set_gpe(ACPI_GPE_CONDITIONAL_ENABLE).
This patch thus converts acpi_set_gpe(ACPI_GPE_ENABLE) into
acpi_hw_low_set_gpe(ACPI_GPE_ENABLE) to achieve a seperate GPE enabling API.
Drivers then are encouraged to use this API when they need to switch
to/from the GPE polling mode.
Note that the acpi_set_gpe()/acpi_finish_gpe() should be first introduced to
Linux using a divergence reduction patch before sending a linuxized version
of this patch. Lv Zheng.
Link: https://github.com/acpica/acpica/commit/da9a83e1
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This can help to reduce source code differences between Linux and ACPICA
upstream. Further driver cleanups also require these APIs to eliminate GPE
storms.
1. acpi_set_gpe(): An API that driver should invoke in the case it wants
to disable/enable IRQ without honoring the reference
count implemented in the acpi_disable_gpe() and
acpi_enable_gpe(). Note that this API should only be
invoked inside a acpi_enable_gpe()/acpi_disable_gpe()
pair.
2. acpi_finish_gpe(): Drivers returned ACPI_REENABLE_GPE unset from the
GPE handler should use this API instead of
invoking acpi_set_gpe()/acpi_enable_gpe() to
re-enable the GPE.
The GPE APIs can be invoked inside of a GPE handler or in the task context
with a driver provided lock held. This driver provided lock is safe to be
held in the GPE handler by the driver.
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPICA commit 199cad16530a45aea2bec98e528866e20c5927e1
Since whether the GPE should be disabled/enabled/cleared should only be
determined by the GPE driver's state machine:
1. GPE should be disabled if the driver wants to switch to the GPE polling
mode when a GPE storm condition is indicated and should be enabled if
the driver wants to switch back to the GPE interrupt mode when all of
the storm conditions are cleared. The conditions should be protected by
the driver's specific lock.
2. GPE should be enabled if the driver has accepted more than one request
and should be disabled if the driver has completed all of the requests.
The request count should be protected by the driver's specific lock.
3. GPE should be cleared either when the driver is about to handle an edge
triggered GPE or when the driver has completed to handle a level
triggered GPE. The handling code should be protected by the driver's
specific lock.
Thus the GPE enabling/disabling/clearing operations are likely to be
performed with the driver's specific lock held while we currently cannot do
this. This is because:
1. We have the acpi_gbl_gpe_lock held before invoking the GPE driver's
handler. Driver's specific lock is likely to be held inside of the
handler, thus we can see some dead lock issues due to the reversed
locking order or recursive locking. In order to solve such dead lock
issues, we need to unlock the acpi_gbl_gpe_lock before invoking the
handler. BZ 1100.
2. Since GPE disabling/enabling/clearing should be determined by the GPE
driver's state machine, we shouldn't perform such operations inside of
ACPICA for a GPE handler to mess up the driver's state machine. BZ 1101.
Originally this patch includes a logic to flush GPE handlers, it is dropped
due to the following reasons:
1. This is a different issue;
2. Linux OSL has fixed this by flushing SCI in acpi_os_wait_events_complete().
We will pick up this topic when the Linux OSL fix turns out to be not
sufficient.
Note that currently the internal operations and the acpi_gbl_gpe_lock are
also used by ACPI_GPE_DISPATCH_METHOD and ACPI_GPE_DISPATCH_NOTIFY. In
order not to introduce regressions, we add one
ACPI_GPE_DISPATCH_RAW_HANDLER type to be distiguished from
ACPI_GPE_DISPATCH_HANDLER. For which the acpi_gbl_gpe_lock is unlocked before
invoking the GPE handler and the internal enabling/disabling operations are
bypassed to allow drivers to perform them at a proper position using the
GPE APIs and ACPI_GPE_DISPATCH_RAW_HANDLER users should invoke acpi_set_gpe()
instead of acpi_enable_gpe()/acpi_disable_gpe() to bypass the internal GPE
clearing code in acpi_enable_gpe(). Lv Zheng.
Known issues:
1. Edge-triggered GPE lost for frequent enablings
On some buggy silicon platforms, GPE enable line may not be directly
wired to the GPE trigger line. In that case, when GPE enabling is
frequently performed for edge-triggered GPEs, GPE status may stay set
without being triggered.
This patch may maginify this problem as it allows GPE enabling to be
parallel performed during the process the GPEs are handled.
This is an existing issue, because:
1. For task context:
Current ACPI_GPE_DISPATCH_METHOD practices have proven that this
isn't a real issue - we can re-enable edge-triggered GPE in a work
queue where the GPE status bit might already be set.
2. For IRQ context:
This can even happen when the GPE enabling occurs before returning
from the GPE handler and after unlocking the GPE lock.
Thus currently no code is included to protect this.
Link: https://github.com/acpica/acpica/commit/199cad16
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPICA commit 8990e73ab2aa15d6a0068b860ab54feff25bee36
Link: https://github.com/acpica/acpica/commit/8990e73a
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
