PCI/PM: Resume subordinate bus in bus type callbacks

Calling pci_resume_bus() on the secondary bus from pci_power_up() as it is
done now is questionable, because it depends on the mandatory bridge
power-up delays that are only covered by the PCI bus type PM callbacks.

For this reason, move the subordinate bus resume to those callbacks too and
use the observation that if a bridge is being powered-up during resume from
system-wide suspend, it may be still desirable to runtime-resume its
subordinate bus after completing the system-wide transition (in case the
resume of the devices on that bus is skipped during it).

Link: https://lore.kernel.org/r/3190097.aeNJFYEL58@kreacher
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

1 files changed, 0 insertions, 15 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 9ecce435fb3f..e6c7f48e8b07 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1310,21 +1310,6 @@ static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout)
 int pci_power_up(struct pci_dev *dev)
 {
 	pci_platform_power_transition(dev, PCI_D0);
-
-	/*
-	 * Mandatory power management transition delays are handled in
-	 * pci_pm_resume_noirq() and pci_pm_runtime_resume() of the
-	 * corresponding bridge.
-	 */
-	if (dev->runtime_d3cold) {
-		/*
-		 * When powering on a bridge from D3cold, the whole hierarchy
-		 * may be powered on into D0uninitialized state, resume them to
-		 * give them a chance to suspend again
-		 */
-		pci_resume_bus(dev->subordinate);
-	}
-
 	return pci_raw_set_power_state(dev, PCI_D0);
 }