On Tue, Jun 25, 2019 at 02:09:12PM +0200, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > In pci_pm_complete() there are checks to decide whether or not to > resume devices that were left in runtime-suspend during the preceding > system-wide transition into a sleep state. They involve checking the > current power state of the device and comparing it with the power > state of it set before the preceding system-wide transition, but the > platform component of the device's power state is not handled > correctly in there. > > Namely, on platforms with ACPI, the device power state information > needs to be updated with care, so that the reference counters of > power resources used by the device (if any) are set to ensure that > the refreshed power state of it will be maintained going forward. > > To that end, introduce a new ->refresh_state() platform PM callback > for PCI devices, for asking the platform to refresh the device power > state data and ensure that the corresponding power state will be > maintained going forward, make it invoke acpi_device_update_power() > (for devices with ACPI PM) on platforms with ACPI and make > pci_pm_complete() use it, through a new pci_refresh_power_state() > wrapper function. > > Fixes: a0d2a959d3da (PCI: Avoid unnecessary resume after direct-complete) > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> I also tested this on Ice Lake system and did not see any issues over several suspend-to-ram cycles.
