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

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Date:	Sat, 14 Sep 2013 03:38:20 +0200
From:	"Rafael J. Wysocki" <rjw@...k.pl>
To:	Linux PCI <linux-pci@...r.kernel.org>
Cc:	ACPI Devel Maling List <linux-acpi@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>,
	Linux PM list <linux-pm@...r.kernel.org>,
	Huang Ying <ying.huang@...el.com>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	Matthew Garrett <mjg59@...f.ucam.org>,
	"David E. Box" <david.e.box@...el.com>
Subject: [PATCH] PCI / ACPI / PM: Clear pme_poll for devices in D3cold on wakeup

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

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@...el.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Cc: 3.6+ <stable@...r.kernel.org> # 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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