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 <[email protected]> Fri Dec 20 00:09:12 2013 > Committer: Rafael J. Wysocki <[email protected]> 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. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
