On Thu, 2021-05-06 at 16:48 -0500, Bjorn Helgaas wrote:
> [+cc Rafael, Andreas, linux-pm]
>
> On Thu, May 06, 2021 at 08:38:20PM +0300, Konstantin Kharlamov wrote:
> > On Macbook 2013 resuming from s2idle results in external monitor no
> > longer being detected, and dmesg having errors like:
> >
> > pcieport 0000:06:00.0: can't change power state from D3hot to D0 (config
> > space inaccessible)
> >
> > and a stacktrace. The reason turned out that the hw that the quirk
> > powers off does not get powered on back on resume.
>
> quirk_apple_poweroff_thunderbolt() was added in 2014 by 1df5172c5c25
> ("PCI: Suspend/resume quirks for Apple thunderbolt"). It claims
> "power is automatically restored before resume," so there must be
> something special about s2idle that prevents the power-on.
>
> IIUC this change will reduce the s2idle power savings. I would feel
> better about this if we understood what the difference was.
>
> > Thus, add a check for s2idle to the quirk, and do nothing if the suspend
> > mode is s2idle.
>
> Obviously the *hardware* hasn't changed since 1df5172c5c25. Is s2idle
> something that wasn't tested back then, or is this problem connected
> to an s2idle change since then? Can we identify a commit that
> introduced this problem? That would help with backporting or stable
> tags.
>
> > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=212767
>
> Thanks for this! Would you mind attaching the output of
> "sudo lspci -vvv"? If you attach any other dmesg, could you
> use "dmesg --color=never" so the log doesn't include all the
> escape characters?
Thank you! So, just to be clear: in lieu of Lukas Wunner's reply, do you still want `lspci` and `dmesg` outputs, or are you okay with the information Lukas provided?
And while on it, an unrelated question to you as a maintainer: I never contributed to the kernel before: in case you are okay with the patch, what happens now that I got R-b, should I resend a v2 of it with the R-b added?
