Re: [PATCH] acpi: video: improve quirk check

From: Rafael J. Wysocki
Date: Sun Aug 04 2013 - 10:04:43 EST

On Sunday, August 04, 2013 01:54:21 AM Felipe Contreras wrote:
> On Sat, Aug 3, 2013 at 8:47 PM, Aaron Lu <aaron.lwe@xxxxxxxxx> wrote:
> > On Sun, Aug 4, 2013 at 6:20 AM, Felipe Contreras
> > <felipe.contreras@xxxxxxxxx> wrote:
> >> On Sat, Aug 3, 2013 at 4:40 PM, Rafael J. Wysocki <rjw@xxxxxxx> wrote:
> >>> Do we still need to revert commit efaa14c if this patch is applied?
> >>
> >> I guess not. At least in this machine changing the backlight works
> >> correctly, whereas in v3.11-rc3 it was all weird, and v3.7-v3.10
> >> didn't work at all. I cannot see how it would affect negatively other
> >> machines.
> >
> > That commit makes hotkey emit notifications, and it's not the
> > problem of "booting into a black screen", that problem is due to
> > broken _BQC.
> The broken _BQC has been there for quite some time, hasn't it?
> Either way, without efaa14c, changing the backlight doesn't work at
> all either way, so there's no black screen, because there cannot be.
> > BTW, the efaa14c will also make screen off at level 0 according
> > to Felipe, who consider this is a bug. But since it is required to
> > let firmware emit notifications on hotkey press, I think user will
> > want it.
> With or without efaa14c, level 0 makes the screen off, or at least it
> would, if the control worked at all. So efaa14c is one step forward,
> but two back, my patch removes the two steps back, but we are still
> not at the level of what my blacklisting patch does, for that we would
> need to fix two issues:
> 1. Fix the retrieval of the last level at boot
> 2. Fix level 0 (yes, I consider that a regression)
> But we cannot achieve either of those for v3.11, the only
> possibilities seem to be either a) revert efaa14c, or b) keep it and
> apply my patch. Anything else doesn't seem to be a possible or
> sensible option, and I vote for b).

I've already said I'm going to do that for 3.11.


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