linux_dsm_epyc7002/drivers
Lukas Wunner e4cb81d7e4 vga_switcheroo: Add support for switching only the DDC
Originally by Seth Forshee <seth.forshee@canonical.com>, 2012-10-04:
    During graphics driver initialization it's useful to be able to mux
    only the DDC to the inactive client in order to read the EDID. Add
    a switch_ddc callback to allow capable handlers to provide this
    functionality, and add vga_switcheroo_switch_ddc() to allow DRM
    to mux only the DDC.

Modified by Dave Airlie <airlied@gmail.com>, 2012-12-22:
    I can't figure out why I didn't like this, but I rewrote this [...]
    to lock/unlock the ddc lines [...]. I think I'd prefer something
    like that otherwise the interface got really ugly.

Modified by Lukas Wunner <lukas@wunner.de>, 2015-04 - 2015-10:
    Change semantics of ->switch_ddc handler callback to return previous
    DDC owner. Original version tried to determine previous DDC owner
    with find_active_client() but this fails if the inactive client
    registers before the active client.

    Don't lock vgasr_mutex in _lock_ddc() / _unlock_ddc(), it can cause
    deadlocks because (a) during switch (with vgasr_mutex already held),
    GPU is woken and probes its outputs, tries to re-acquire vgasr_mutex
    to lock DDC lines; (b) Likewise during switch, GPU is suspended and
    calls cancel_delayed_work_sync() to stop output polling, if poll
    task is running at this moment we may wait forever for it to finish.

    Instead, lock mux_hw_lock when unregistering the handler because
    the only reason why we'd want to lock vgasr_mutex in _lock_ddc() /
    _unlock_ddc() is to block the handler from disappearing while DDC
    lines are switched.

    Also acquire mux_hw_lock in stage2 to avoid race condition where
    reading the EDID and switching happens simultaneously. Likewise on
    MIGD / MDIS commands and on runtime suspend.

    v2.1: Overhaul locking, squash commits (Daniel Vetter)

    v2.2: Readability improvements (Thierry Reding)

    v2.3: Overhaul locking once more

    v2.4: Retain semantics of ->switchto handler callback to switch all
          pins, including DDC (Daniel Vetter)

    v5:   Rename ddc_lock to mux_hw_lock: Since we acquire this both
          when calling ->switch_ddc and ->switchto, it protects not just
          access to the DDC lines but to the mux in general. This is in
          line with the DRM convention to use low-level locks to avoid
          concurrent hw access (e.g. i2c, dp_aux) which are often called
          hw_lock (Daniel Vetter)

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=88861
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=61115
Tested-by: Lukas Wunner <lukas@wunner.de>
    [MBP  9,1 2012  intel IVB + nvidia GK107  pre-retina  15"]
Cc: Seth Forshee <seth.forshee@canonical.com>
Cc: Dave Airlie <airlied@gmail.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/e81ae9722b84c5ed591805fee3ea6dbf5dc6c4b3.1452525860.git.lukas@wunner.de
2016-02-09 11:21:07 +01:00
..
accessibility
acpi Merge branches 'pm-core' and 'pm-domains' 2016-02-06 00:34:01 +01:00
amba
android
ata Merge branch 'for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata 2016-01-11 19:33:59 -08:00
atm
auxdisplay
base Merge branches 'pm-core' and 'pm-domains' 2016-02-06 00:34:01 +01:00
bcma GPIO bulk updates for the v4.5 kernel cycle: 2016-01-17 12:32:01 -08:00
block Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2016-01-24 12:34:13 -08:00
bluetooth Bluetooth: btmrvl: don't send data to firmware while processing suspend 2016-01-06 16:37:14 +01:00
bus vexpress fixes for v4.5 2016-02-01 12:27:18 -08:00
cdrom cdrom: don't open-code memdup_user() 2016-01-06 08:25:24 -05:00
char Fix a compile error on IPMI when ACPI is disabled. 2016-02-03 10:04:58 -08:00
clk ARM: DT updates for v4.5 2016-01-20 18:16:29 -08:00
clocksource Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-01-31 15:49:06 -08:00
connector
cpufreq Merge branches 'pm-cpuidle', 'pm-cpufreq', 'pm-domains' and 'pm-sleep' 2016-01-29 21:45:17 +01:00
cpuidle Merge branches 'pm-cpuidle', 'pm-cpufreq', 'pm-domains' and 'pm-sleep' 2016-01-29 21:45:17 +01:00
crypto crypto: atmel-aes - remove calls of clk_prepare() from atomic contexts 2016-01-30 22:05:17 +08:00
dca
devfreq PM / devfreq: Do not show statistics if it's not ready. 2016-01-13 17:30:33 +09:00
dio
dma dmaengine fixes for 4.5-rc1 2016-01-20 10:15:21 -08:00
dma-buf dma-buf: Remove range-based flush 2016-02-09 09:25:22 +01:00
edac
eisa
extcon
firewire
firmware UBSAN: run-time undefined behavior sanity checker 2016-01-20 17:09:18 -08:00
fmc
fpga
gpio ARM: SoC multiplatform code changes for v4.5 2016-01-20 18:03:56 -08:00
gpu vga_switcheroo: Add support for switching only the DDC 2016-02-09 11:21:07 +01:00
hid asm-generic changes for 4.5 2016-01-20 17:30:20 -08:00
hsi HSI: omap_ssi_port: fix handling of_get_named_gpio result 2016-01-07 16:07:54 +01:00
hv char/misc patches for 4.5-rc1 2016-01-13 10:23:36 -08:00
hwmon hwmon: (fam15h_power) Add bit masking for tdp_limit 2016-01-27 18:48:46 -08:00
hwspinlock drivers/hwspinlock: fix race between radix tree insertion and lookup 2016-02-03 08:28:43 -08:00
hwtracing
i2c i2c: piix4: don't regress on bus names 2016-01-29 11:13:52 +01:00
ide drivers/ide: make ide-scan-pci.c driver explicitly non-modular 2016-01-18 14:12:33 -05:00
idle
iio Second set of IIO fixes for the 4.5 cycle. These ones are mostly 2016-02-01 13:08:26 -08:00
infiniband IB/core: Set correct payload length for RoCEv2 over IPv6 2016-02-02 16:42:22 -05:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2016-01-22 17:20:30 -08:00
iommu iommu/amd: Correct the wrong setting of alias DTE in do_attach 2016-01-29 12:30:47 +01:00
ipack
irqchip Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-01-31 14:48:58 -08:00
isdn Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-01-11 23:55:43 -05:00
leds GPIO bulk updates for the v4.5 kernel cycle: 2016-01-17 12:32:01 -08:00
lguest lguest: Map switcher text R/O 2016-01-12 12:17:28 +01:00
lightnvm lightnvm: introduce factory reset 2016-01-12 08:21:18 -07:00
macintosh
mailbox mailbox: Fix dependencies for !HAS_IOMEM archs 2016-02-02 16:47:14 +05:30
mcb
md Merge branch 'mymd/for-next' into mymd/for-linus 2016-02-03 15:43:59 -08:00
media [media] saa7134-alsa: Only frees registered sound cards 2016-02-04 16:26:10 -02:00
memory ARM: SoC driver updates for v4.5 2016-01-20 18:42:30 -08:00
memstick memstick: use sector_div instead of do_div 2016-01-20 17:09:18 -08:00
message
mfd GPIO bulk updates for the v4.5 kernel cycle: 2016-01-17 12:32:01 -08:00
misc Merge branch 'akpm' (patches from Andrew) 2016-01-21 12:32:08 -08:00
mmc MMC core: 2016-01-22 12:04:21 -08:00
mtd Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2016-01-24 12:50:56 -08:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-02-01 15:56:08 -08:00
nfc
ntb NTB: Fix macro parameter conflict with field name 2016-01-21 19:53:10 -05:00
nubus
nvdimm libnvdimm, pfn: fix restoring memmap location 2016-01-29 17:43:16 -08:00
nvme Merge branch 'for-4.5/nvme' of git://git.kernel.dk/linux-block 2016-01-21 19:58:02 -08:00
nvmem
of Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-02-01 15:56:08 -08:00
oprofile wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
parisc parisc: convert to dma_map_ops 2016-01-20 17:09:18 -08:00
parport
pci Merge branches 'acpi-video' and 'acpi-hotplug' 2016-01-29 21:44:53 +01:00
pcmcia
perf
phy
pinctrl GPIO bulk updates for the v4.5 kernel cycle: 2016-01-17 12:32:01 -08:00
platform vga_switcheroo: Add handler flags infrastructure 2016-02-09 11:21:07 +01:00
pnp PNP: Add Haswell-ULT to Intel MCH size workaround 2016-02-03 01:00:29 +01:00
power power: bq27xxx_battery: Fix bq27541 AveragePower register address 2016-01-14 01:03:18 +01:00
powercap Merge branch 'powercap' 2016-01-12 01:12:40 +01:00
pps
ps3
ptp ptp: ixp46x: use helpers for converting ns to timespec 2016-01-29 12:38:59 -08:00
pwm pwm: Mark all devices as "might sleep" 2016-01-21 15:04:59 +01:00
rapidio rapidio: use kobj_to_dev() 2016-01-20 17:09:18 -08:00
ras
regulator regulator: Update for v4.5 2016-01-15 12:14:47 -08:00
remoteproc virtio: make find_vqs() checkpatch.pl-friendly 2016-01-12 20:47:06 +02:00
reset
rpmsg virtio: make find_vqs() checkpatch.pl-friendly 2016-01-12 20:47:06 +02:00
rtc RTC for 4.5 2016-01-18 12:10:45 -08:00
s390 s390/cio: update measurement characteristics 2016-01-26 12:47:51 +01:00
sbus
scsi drivers/scsi/sg.c: mark VMA as VM_IO to prevent migration 2016-02-03 08:28:43 -08:00
sfi
sh
sn
soc ARM: SoC support for Tegra platforms for v4.5 2016-01-22 17:30:52 -08:00
spi powerpc updates for 4.5 2016-01-15 13:18:47 -08:00
spmi
ssb ssb: mark ssb_bus_register as __maybe_unused 2016-01-19 21:25:57 +02:00
staging dma-buf: Remove range-based flush 2016-02-09 09:25:22 +01:00
target Merge branch 'for-4.5/nvme' of git://git.kernel.dk/linux-block 2016-01-21 19:58:02 -08:00
tc
thermal Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux 2016-01-24 12:43:06 -08:00
thunderbolt
tty TTY/Serial fixes for 4.5-rc2 2016-01-31 17:09:39 -08:00
uio
usb xhci: harden xhci_find_next_ext_cap against device removal 2016-02-04 17:00:10 -08:00
uwb
vfio vfio/noiommu: Don't use iommu_present() to track fake groups 2016-01-27 11:22:25 -07:00
vhost
video wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
virt
virtio virtio_pci: fix use after free on release 2016-01-26 10:18:28 +02:00
vlynq
vme
w1
watchdog watchdog: Fix dependencies for !HAS_IOMEM archs 2016-01-31 16:54:36 +01:00
xen Merge branch 'stable/for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/mm 2016-01-29 15:13:48 -08:00
zorro
Kconfig
Makefile