[PATCH] PCI / ACPI / PM: Clear pme_poll for devices in D3cold on wakeup

From: Rafael J. Wysocki
Date: Fri Sep 13 2013 - 21:27:31 EST


From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

Commit 448bd85 (PCI/PM: add PCIe runtime D3cold support) added a
piece of code to pci_acpi_wake_dev() causing that function to behave
in a special way for devices in D3cold (so that their configuration
registeres are not accessed before those devices are resumed).
However, it didn't take the clearing of the pme_poll flag into
account. That has to be done for all devices, even if they are in
D3cold, or pci_pme_list_scan() will not know that wakeup has been
signaled for the device and will poll its PME Status bit
unnecessarily.

Fix the problem by moving the clearing of the pme_poll flag in
pci_acpi_wake_dev() before the code introduced by commit 448bd85.

Reported-and-tested-by: David E. Box <david.e.box@xxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Cc: 3.6+ <stable@xxxxxxxxxxxxxxx> # 3.6+
---
drivers/pci/pci-acpi.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

Index: linux-pm/drivers/pci/pci-acpi.c
===================================================================
--- linux-pm.orig/drivers/pci/pci-acpi.c
+++ linux-pm/drivers/pci/pci-acpi.c
@@ -47,6 +47,9 @@ static void pci_acpi_wake_dev(acpi_handl
if (event != ACPI_NOTIFY_DEVICE_WAKE || !pci_dev)
return;

+ if (pci_dev->pme_poll)
+ pci_dev->pme_poll = false;
+
if (pci_dev->current_state == PCI_D3cold) {
pci_wakeup_event(pci_dev);
pm_runtime_resume(&pci_dev->dev);
@@ -57,9 +60,6 @@ static void pci_acpi_wake_dev(acpi_handl
if (pci_dev->pme_support)
pci_check_pme_status(pci_dev);

- if (pci_dev->pme_poll)
- pci_dev->pme_poll = false;
-
pci_wakeup_event(pci_dev);
pm_runtime_resume(&pci_dev->dev);


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