On Wed, Jan 15, 2020 at 11:24:47AM +0100, Rafael J. Wysocki wrote: > On Thursday, January 2, 2020 11:39:19 PM CET Anchal Agarwal wrote: > > On Thu, Dec 12, 2019 at 11:10:32PM +0100, Rafael J. Wysocki wrote: > > > On Monday, October 29, 2018 6:52:16 PM CET Anchal Agarwal wrote: > > > > Currently we do not see sleep_enable bit set after guest resumes > > > > from hibernation. Hibernation is triggered in guest on receiving > > > > a sleep trigger from the hypervisor(S4 state). We see that power > > > > button is enabled on wake up from S4 state however sleep button > > > > isn't. > > > > > > I'm not against this change in principle, although it may change behavior > > > in a somewhat unexpected way on some systems. > > > > > Apologies for late response, I was out on vacation. > > Can you please elaborate more on that? > > See below. > > > > > This causes subsequent invocation of sleep state to fail > > > > in the guest. > > > > > > However, can you explain this in a bit more detail? > > > > > I can explain this for my particular case, however, any code path going > > through acpi_hw_legacy_wake path will not have sleep button enabled. Why > > is only power button event enabled and not sleep here? > > Good question and related to the potentially unexpected behavior part. > > Presumably, on some systems the sleep button could not be enabled > automatically as it triggered another suspend right away after that. > > That's speculation, though. > > > In my case, I am using sleep button event to generate S4 state > > which causes guest VM running on xen to hibernate. > > Usually, however, the sleep button is used to trigger transitions into S3 > (or suspend-to-idle on systems that support it). > > > I have found > > in my debugging process that after first resume when kernel goes > > through this code path, sleep button event is not enabled and > > when hypervisor try to generate sci interrupt, its not received in > > the guest since this path does not enable sleep event. > > OK > > So the patch can be applied AFAICS, but if it is reported to cause problems to > happen, it will need to be reverted. > > Please resend the patch with a proper CC list (including Bob, Erik, the ACPICA > devel list etc). > > Thanks! Sure can I add your Reviewed-by or Acked-by? Thanks, Anchal > > >
