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. Thanks, Aaron -- 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
