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? 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
