Hi, On Thu, Oct 29, 2020 at 12:24:53PM +0300, Mika Westerberg wrote: > When a PCI bridge is runtime resumed from D3cold the underlying bus is > walked and the attached devices are runtime resumed as well. However, in > addition to that we also generate a wakeup event for these devices even > though this actually is not a real wakeup event coming from the > hardware. > > Normally this does not cause problems but when combined with > /sys/power/wakeup_count like using the steps below: > > # count=$(cat /sys/power/wakeup_count) > # echo $count > /sys/power/wakeup_count > # echo mem > /sys/power/state > > The system suspend cycle might get aborted at this point if a PCI bridge > that was runtime suspended (D3cold) was runtime resumed for any reason. > The runtime resume calls pci_wakeup_bus() and that generates wakeup > event increasing wakeup_count. > > Since this is not a real wakeup event we can prevent the above from > happening by removing the call to pci_wakeup_event() in > pci_wakeup_bus(). While there rename pci_wakeup_bus() to > pci_resume_bus() to better reflect what it does. Any comments on this? Thanks!
