Commit 730643d3 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Bjorn Helgaas
Browse files

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: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
parent 9a605831

drivers/pci/pci-driver.c

+13 −2
Original line number Diff line number Diff line
@@ -564,6 +564,17 @@ static void pci_pm_default_resume_early(struct pci_dev *pci_dev) 
	pci_pme_restore(pci_dev);

}



static void pci_pm_bridge_power_up_actions(struct pci_dev *pci_dev)

{

	pci_bridge_wait_for_secondary_bus(pci_dev);

	/*

	 * 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(pci_dev->subordinate);

}



#endif /* CONFIG_PM */



#ifdef CONFIG_PM_SLEEP
@@ -939,7 +950,7 @@ static int pci_pm_resume_noirq(struct device *dev) 
	pcie_pme_root_status_cleanup(pci_dev);



	if (!skip_bus_pm && prev_state == PCI_D3cold)

		pci_bridge_wait_for_secondary_bus(pci_dev);

		pci_pm_bridge_power_up_actions(pci_dev);



	if (pci_has_legacy_pm_support(pci_dev))

		return 0;
@@ -1326,7 +1337,7 @@ static int pci_pm_runtime_resume(struct device *dev) 
	pci_pm_default_resume(pci_dev);



	if (prev_state == PCI_D3cold)

		pci_bridge_wait_for_secondary_bus(pci_dev);

		pci_pm_bridge_power_up_actions(pci_dev);



	if (pm && pm->runtime_resume)

		error = pm->runtime_resume(dev);

drivers/pci/pci.c

+0 −15
Original line number Diff line number Diff line
@@ -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);

}