PCIe PME and native hotplug share the same interrupt number, so hotplug
interrupts are also processed by PME. In some cases, e.g., a Link Down
interrupt, a device may be present but unreachable, so when we try to
read its Root Status register, the read fails and we get all ones data
(0xffffffff).
Previously, we interpreted that data as PCI_EXP_RTSTA_PME being set, i.e.,
"some device has asserted PME," so we scheduled pcie_pme_work_fn(). This
caused an infinite loop because pcie_pme_work_fn() tried to handle PME
requests until PCI_EXP_RTSTA_PME is cleared, but with the link down,
PCI_EXP_RTSTA_PME can't be cleared.
Check for the invalid 0xffffffff data everywhere we read the Root Status
register.
1469d17dd3 ("PCI: pciehp: Handle invalid data when reading from
non-existent devices") added similar checks in the hotplug driver.
Signed-off-by: Qiang Zheng <zhengqiang10@huawei.com>
[bhelgaas: changelog, also check in pcie_pme_work_fn(), use "~0" to follow
other similar checks]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Commit 76cde7e495 (PCI / PM: Make PCIe PME interrupts wake up from
suspend-to-idle) went too far with preventing pcie_pme_work_fn() from
clearing the root port's PME Status and re-enabling the PME interrupt
which should be done for PMEs to work correctly after system resume.
The failing scenario is as follows:
1. pcie_pme_suspend() finds that the PME IRQ should be designated
for system wakeup, so it calls enable_irq_wake() and then sets
data->suspend_level to PME_SUSPEND_WAKEUP.
2. PME interrupt happens at this point.
3. pcie_pme_irq() runs, disables the PME interrupt and queues up
the execution of pcie_pme_work_fn().
4. pcie_pme_work_fn() runs before pcie_pme_resume() and breaks out
of the loop right away, because data->suspend_level is not
PME_SUSPEND_NONE, and it doesn't re-enable the PME interrupt
for the same reason.
5. pcie_pme_resume() runs and simply calls disable_irq_wake()
without re-enabling the PME interrupt (because data->suspend_level
is not PME_SUSPEND_NONE), so the PME interrupt remains disabled
and the PME Status remains set.
To fix this notice that there is no reason why pcie_pme_work_fn()
should behave in a special way during system resume if the PME
interrupt is not disabled by pcie_pme_suspend() and partially revert
commit 76cde7e495 and restore the previous (and correct) behavior
of pcie_pme_work_fn().
Fixes: 76cde7e495 (PCI / PM: Make PCIe PME interrupts wake up from suspend-to-idle)
Reported-and-tested-by: Naresh Solanki <naresh.solanki@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
The run_wake flag in struct dev_pm_info is used to indicate whether
or not the device is capable of generating remote wakeup signals at
run time (or in the system working state), but the distinction
between runtime remote wakeup and system wakeup signaling has always
been rather artificial. The only practical reason for it to exist
at the core level was that ACPI and PCI treated those two cases
differently, but that's not the case any more after recent changes.
For this reason, get rid of the run_wake flag and, when applicable,
use device_set_wakeup_capable() and device_can_wakeup() instead of
device_set_run_wake() and device_run_wake(), respectively.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
The pme_interrupt flag in struct pci_dev is set when PMEs generated
by the device are going to be signaled via root port PME interrupts.
Ironically enough, that information is only used by the code setting
up device wakeup through ACPI which returns as soon as it sees the
pme_interrupt flag set while setting up "remote runtime wakeup".
That is questionable, however, because in theory there may be PCIe
devices using out-of-band PME signaling under root ports handled
by the native PME code or devices requiring wakeup power setup to be
carried out by AML. For such devices, ACPI wakeup should be invoked
regardless of whether or not native PME signaling is used in general.
For this reason, drop the pme_interrupt flag and rework the code
using it which then allows the ACPI-based device wakeup handling
in PCI to be consolidated to use one code path for both "runtime
remote wakeup" and system wakeup (from sleep states).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
We already log a "Signaling PME" whenever the PME service driver claims a
Root Port. In fact, we also log the same message for every device in the
hierarchy below the Root Port.
Log the "Signaling PME" once (only for the Root Port, since we can
trivially find out which devices are below the Root Port), and include the
IRQ number in the message to help connect the dots with /proc/interrupts.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Since we register pcie_pme_driver only for PCI_EXP_TYPE_ROOT_PORT, the PME
driver never claims Root Complex Event Collectors.
Remove unused code related to Root Complex Event Collectors.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This code is not being built as a module by anyone:
config PCIE_PME
def_bool y
depends on PCIEPORTBUS && PM
Remove traces of modularity so that when reading the driver there is no
doubt it is builtin-only.
Also delete the .remove function, since that doesn't seem to have a
sensible use case. With "normal" endpoint drivers, we have in the past set
the suppress_bind_attrs bit to make it clear that the use of ".remove" in a
builtin driver was deleted, but here for PCI, it seems overkill to jump
through the pcie_port_service_driver and into the struct device_driver in
order to finally try and do something similar with the bind setting.
Note that for non-modular code, module_init() translates to
device_initcall().
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Previously we had this:
if (wakeup)
ret = enable_irq_wake(...);
if (!wakeup || ret)
...
"ret" is only evaluated when "wakeup" is true, and it is always initialized
in that case, but gcc isn't smart enough to figure that out and warns:
drivers/pci/pcie/pme.c:414:14: warning: 'ret' may be used uninitialized in this function [-Wmaybe-uninitialized]
Restructure the code slightly to make it easier for gcc (and maybe for
humans as well).
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com
We've already looked up srv->port a few lines earlier, and there's no need
to do it again. Remove the redundant lookup.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com
If the irqchip handling the PCIe PME interrupt is not able
to enable interrupt wakeup we should properly reflect this
in the PME suspend status.
This fixes a kernel warning on resume, where it would try
to disable the irq wakeup that failed to be activated while
suspending, for example:
WARNING: CPU: 0 PID: 609 at kernel/irq/manage.c:536 irq_set_irq_wake+0xc0/0xf8()
Unbalanced IRQ 384 wake disable
Fixes: 76cde7e495 (PCI / PM: Make PCIe PME interrupts wake up from suspend-to-idle)
Reported-and-tested-by: Richard Zhu <richard.zhu@freescale.com>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
To make PCIe PME interrupts wake up the system from suspend to idle,
make the PME driver use enable_irq_wake() on the IRQ during system
suspend (if there are any wakeup devices below the given PCIe port)
without disabling PME interrupts. This way, an interrupt will still
trigger if a wakeup event happens and the system will be woken up (or
system suspend in progress will be aborted) by means of the new
mechanics introduced previously.
This change allows Wake-on-LAN to be used for wakeup from
suspend-to-idle on my MSI Wind tesbed netbook.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Merge quoted strings that are broken across lines into a single entity.
The compiler merges them anyway, but checkpatch complains about it, and
merging them makes it easier to grep for strings.
No functional change.
[bhelgaas: changelog, do the same for everything under drivers/pci]
Signed-off-by: Ryan Desfosses <ryan@desfo.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Fix whitespace, capitalization, and spelling errors. No functional change.
I know "busses" is not an error, but "buses" was more common, so I used it
consistently.
Signed-off-by: Marta Rybczynska <rybczynska@gmail.com> (pci_reset_bridge_secondary_bus())
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PCIe PME doesn't depend on ACPI, so remove the #includes and
Kconfig dependency.
Based-on-patch-by: Andrew Murray <Andrew.Murray@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Introduce an inline function pci_pcie_type(dev) to extract PCIe
device type from pci_dev->pcie_flags_reg field, and prepare for
removing pci_dev->pcie_type.
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The land of PCI power management is a land of sorrow and ugliness,
especially in the area of signaling events by devices. There are
devices that set their PME Status bits, but don't really bother
to send a PME message or assert PME#. There are hardware vendors
who don't connect PME# lines to the system core logic (they know
who they are). There are PCI Express Root Ports that don't bother
to trigger interrupts when they receive PME messages from the devices
below. There are ACPI BIOSes that forget to provide _PRW methods for
devices capable of signaling wakeup. Finally, there are BIOSes that
do provide _PRW methods for such devices, but then don't bother to
call Notify() for those devices from the corresponding _Lxx/_Exx
GPE-handling methods. In all of these cases the kernel doesn't have
a chance to receive a proper notification that it should wake up a
device, so devices stay in low-power states forever. Worse yet, in
some cases they continuously send PME Messages that are silently
ignored, because the kernel simply doesn't know that it should clear
the device's PME Status bit.
This problem was first observed for "parallel" (non-Express) PCI
devices on add-on cards and Matthew Garrett addressed it by adding
code that polls PME Status bits of such devices, if they are enabled
to signal PME, to the kernel. Recently, however, it has turned out
that PCI Express devices are also affected by this issue and that it
is not limited to add-on devices, so it seems necessary to extend
the PME polling to all PCI devices, including PCI Express and planar
ones. Still, it would be wasteful to poll the PME Status bits of
devices that are known to receive proper PME notifications, so make
the kernel (1) poll the PME Status bits of all PCI and PCIe devices
enabled to signal PME and (2) disable the PME Status polling for
devices for which correct PME notifications are received.
Tested-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Make wakeup events be reported by the PCI subsystem before attempting to
resume devices or queuing up runtime resume requests for them, because
wakeup events should be reported as soon as they have been detected.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
I noticed that PCI Express PMEs don't work on my Toshiba Portege R500
after the system has been woken up from a sleep state by a PME
(through Wake-on-LAN). After some investigation it turned out that
the BIOS didn't clear the Root PME Status bit in the root port that
received the wakeup PME and since the Requester ID was also set in
the port's Root Status register, any subsequent PMEs didn't trigger
interrupts.
This problem can be avoided by clearing the Root PME Status bits in
all PCI Express root ports during early resume. For this purpose,
add an early resume routine to the PCIe port driver and make this
driver be always registered, even if pci_ports_disable is set (in
which case the driver's only function is to provide the early
resume callback).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
The PCIe PME code only consists of one file, so it doesn't need to
occupy its own directory. Move it to drivers/pci/pcie/pme.c and
remove the contents of drivers/pci/pcie/pme .
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
