Re: Linux 3.11-rc2

From: Rafael J. Wysocki
Date: Mon Jul 22 2013 - 09:27:45 EST


On Monday, July 22, 2013 03:15:38 PM Martin Steigerwald wrote:
> Am Montag, 22. Juli 2013, 15:02:22 schrieb Rafael J. Wysocki:
> > On Monday, July 22, 2013 12:08:40 AM James Hogan wrote:
> > > On 21 July 2013 20:53, Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> wrote:
> > > > (b) we had a late change to how ACPI backlight handling is done on
> > > >
> > > > certain machines, and while this kind of thing really shouldn't be
> > > > done outside the merge window, I ended up pulling it anyway. But I'd
> > > > *really* like to have people test this thing particularly on laptops
> > > > with intel-based graphics. It should only matter (and hopefully
> > > > improve things) for the newer ones with BIOSes designed for Windows 8,
> > > > but hey, the more testing, the better. Backlight handling has beenin
> > > > painful before, so I'm mentioning this explicitly.
> > >
> > > 8c5bd7a "ACPI / video / i915: No ACPI backlight if firmware expects
> > > Windows 8" breaks backlight control for me because
> > > /sys/class/backlight/acpi_video0 disappears, and
> > > /sys/class/backlight/intel_backlight doesn't seem to have any effect.
> > >
> > > Note that acpi_video0 only worked because I was applying "[PATCH]
> > > drm/i915: quirk no PCH_PWM_ENABLE for Dell XPS13 backlight" [1], so
> > > strictly speaking mainline already didn't work.
> >
> > James, sorry for breaking things for you. The patch you're mentioning is
> > going to hit the mainline at one point anyway I suppose.
>
> Dunno whether thats related, but after locking screen today and screen blanker
> kicking in (just a blank screen), I was not able to reactivate the display
> again by typing a key or so unless I closed the laptop display lid, let the
> machine suspend (to ram) and opened it again.
>
> Plain 3.11-rc2 on ThinkPad T520:

Well, please try to revert commits efaa14c and 8c5bd7a (in this order) and see
if that helps.

Thanks,
Rafael


--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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