Re: [PATCH] ACPI / video: Add HP EliteBook Revolve 810 to the blacklist

From: Mika Westerberg
Date: Wed Feb 12 2014 - 04:27:15 EST


On Wed, Feb 12, 2014 at 10:31:59AM +0800, Aaron Lu wrote:
> On 02/07/2014 06:25 PM, Mika Westerberg wrote:
> > On Fri, Feb 07, 2014 at 09:29:58AM +0800, Aaron Lu wrote:
> >> On 02/03/2014 06:59 PM, Mika Westerberg wrote:
> >>> On HP EliteBook Revolve 810 the ACPI backlight device doesn't work as
> >>> expected. For example when resuming from system sleep, it seems to lose
> >>> backlight settings.
> >>>
> >>> Forcing Intel driver fixes the problem so add this machine the ACPI
> >>> video detect blacklist.
> >>
> >> For reference's purpose, can you please file a bug to kernel bugzilla
> >> under the ACPI/Power-Video category and attach the acpidump and dmesg
> >> there? Thanks.
> >
> > Done, the bug is here:
> >
> > https://bugzilla.kernel.org/show_bug.cgi?id=70231
> >
> > I noticed that using only the acpi_video0 for tuning backlight works but if
> > I use intel_backlight directly, on resume I get values from acpi_video0
> > instead. I'm not really familiar how this is supposed to work, though so
> > please let me know if I'm missing something.
>
> Thanks for the report, as communicated on the bug page, your system is
> already blacklisted for win8 by commit:
>
> commit 2d4054d8422462cb2771fdb4eb1925df55d2b320
> Author: Takashi Iwai <tiwai@xxxxxxx> Fri Dec 20 00:09:12 2013
> Committer: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Fri Dec 20 22:50:56 2013
>
> ACPI: Blacklist Win8 OSI for some HP laptop 2013 models
>
> And the fact that acpi_video interface works made it not appropriate to
> add your system into the video_detect_dmi_table. You can just use acpi_video
> interface and everything should work fine.

OK, thanks for the investigation Aaron.

I have few questions, though.

1) Is it always right thing to do to use acpi_video0 over anything else?
In my case that device first disapeared and then reappeared so I got kind
of confused about that. I'm going to tune my scripts to use acpi_video0 as
you suggested.

2) What should we do with this commit? It is already in mainline so I
guess revert is the sane thing to do.

I should have asked/investigated this more before submitting the patch.
Sorry about that.
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