On Tuesday, July 15, 2014 02:06:21 PM Aaron Lu wrote: > On 07/15/2014 03:17 AM, Rafael J. Wysocki wrote: > > On Monday, July 14, 2014 08:56:29 PM Julian Wollrath wrote: > >> Am Mon, 14 Jul 2014 21:10:47 +0200 > >> schrieb "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>: > >> > >>> On Monday, July 14, 2014 09:02:34 PM Rafael J. Wysocki wrote: > >>>> On Monday, July 14, 2014 08:34:22 PM Julian Wollrath wrote: > >>>>> Am Mon, 14 Jul 2014 20:21:19 +0200 > >>>>> schrieb "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>: > >>>>> > >>>>>> On Saturday, July 12, 2014 06:24:52 PM Julian Wollrath wrote: > >>>>>>> Hi, > >>>>>>> > >>>>>>>> changing the brightness on my Thinkpad X230 with Intel > >>>>>>>> HD4000 graphics, stopped working after commit 886129a8eebe > >>>>>>>> (ACPI / video: change acpi-video brightness_switch_enabled > >>>>>>>> default to 0). Changing it back to 1, fixes the problem, if > >>>>>>>> "acpi_osi=!Windows 2012" is also set. Before that commit > >>>>>>>> just setting "acpi_osi=!Windows 2012" was enough to get > >>>>>>>> changing the brightness working. > >>>>>>> > >>>>>>> small correction: It setting "acpi_osi=!Windows 2012" does > >>>>>>> only help when using a kernel with commit 886129a8eebe as > >>>>>>> HEAD, with v3.16-rc4 setting > >>>>>>> video.brightness_switch_enabled=1 and acpi_osi=!Windows 2012 > >>>>>>> or just one of them, does not make changing the brightness > >>>>>>> work again. > >>>>>> > >>>>>> And reverting commit 751109aad583 (ACPI / video: Change the > >>>>>> default for video.use_native_backlight to 1) make that last > >>>>>> problem go away, right? > >>>>>> > >>>>>> We are going to rever commit 886129a8eebe for other reasons, so > >>>>>> can you please revert it from 3.16-rc5 on your system and > >>>>>> report back? > >>>>> Yes, with both 751109aad583 and 886129a8eebe reverted, changing > >>>>> the brightness works again. > >>>> > >>>> What if you revert 886129a8eebe alone? > >>> > >>> I mean, what exactly do you need to pass to the kernel command line > >>> in that case to make brightness switching work? > >> I need to pass > >> acpi_osi="!Windows 2012" video.brightness_switch_enabled=1 video.use_native_backlight=-1 > >> > >> If I leave one of these parameters out, the brightness switch stops > >> working. > > > > With 886129a8eebe reverted you should not need video.brightness_switch_enabled=1. > > > > Aaron, what do you think? > > I agree. > > I suppose Julian is not using an standard GUI so he needs the in kernel > processing of the backlight event. And his laptop has a broken ACPI > interface in Win8 mode, so he also needs the "!Windows 2012" option. > > With a standard GUI environment, his system would have only one > interface left: the GPU one and everything should work. But of course, > that may not be his config. Well, do we need to revert 751109aad583 too, then? It seems that it may break other systems without a desktop environment, may it not? Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
