PCI / PM: Avoid resuming more devices during system suspend

Commit bac2a909a096 (PCI / PM: Avoid resuming PCI devices during
system suspend) introduced a mechanism by which some PCI devices that
were runtime-suspended at the system suspend time might be left in
that state for the duration of the system suspend-resume cycle.
However, it overlooked devices that were marked as capable of waking
up the system just because PME support was detected in their PCI
config space.

Namely, in that case, device_can_wakeup(dev) returns 'true' for the
device and if the device is not configured for system wakeup,
device_may_wakeup(dev) returns 'false' and it will be resumed during
system suspend even though configuring it for system wakeup may not
really make sense at all.

To avoid this problem, simply disable PME for PCI devices that have
not been configured for system wakeup and are runtime-suspended at
the system suspend time for the duration of the suspend-resume cycle.

If the device is in D3cold, its config space is not available and it
shouldn't be written to, but that's only possible if the device
has platform PM support and the platform code is responsible for
checking whether or not the device's configuration is suitable for
system suspend in that case.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 108a3118ace7..8dfb144b8ccf 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -684,10 +684,21 @@ static int pci_pm_prepare(struct device *dev)
         return pci_dev_keep_suspended(to_pci_dev(dev));
 }
 
+static void pci_pm_complete(struct device *dev)
+{
+        struct device_driver *drv = dev->driver;
+        struct pci_dev *pci_dev = to_pci_dev(dev);
+
+        pci_dev_complete_resume(pci_dev);
+
+        if (drv && drv->pm && drv->pm->complete)
+                drv->pm->complete(dev);
+}
 
 #else /* !CONFIG_PM_SLEEP */
 
 #define pci_pm_prepare  NULL
+#define pci_pm_complete NULL
 
 #endif /* !CONFIG_PM_SLEEP */
 
@@ -1218,6 +1229,7 @@ static int pci_pm_runtime_idle(struct device *dev)
 
 static const struct dev_pm_ops pci_dev_pm_ops = {
         .prepare = pci_pm_prepare,
+        .complete = pci_pm_complete,
         .suspend = pci_pm_suspend,
         .resume = pci_pm_resume,
         .freeze = pci_pm_freeze,