Thanks Daniel so I'm taking back my bug report on the i915 and claiming this as a bug against the acpi_video stack. What sort of information would the ACPI folk like from me to help diagnose this? Here's a dmesg dump of all ACPI messages. http://pastebin.com/b4XKe5Fk Tom ----- Original Message ----- > From: "Daniel Vetter" <daniel.vetter at ffwll.ch> > To: "Tom St Denis" <tstdenis at elliptictech.com> > Cc: linux-kernel at vger.kernel.org, "intel-gfx" <intel-gfx at lists.freedesktop.org>, "dri-devel" > <dri-devel at lists.freedesktop.org> > Sent: Sunday, 2 December, 2012 9:42:39 AM > Subject: Re: Brightness control fails between 3.6.8 and 3.7.0-rc7 (Intel 915/Dell Vostro 3560) > > On Sun, Dec 2, 2012 at 2:49 PM, Tom St Denis > <tstdenis at elliptictech.com> wrote: > > Ok so on v3.7-rc1 [and I suspect up] I can manually control the > > brightness by echoing to > > > > /sys/class/backlight/intel_backlight/brightness > > > > But I still can't use the buttons to control it (it only goes one > > tick down from max and stops there). I'm using GNOME3 from a > > x86_64 unstable debian install [up to date with latest]. > > > > I just noticed that under v3.7 I have a new directory > > /sys/class/backlight/acpi_video1 which is what GNOME is actually > > controlling. I can't disable ACPI video control so is there a > > workaround? > > Hah, acpi registered a broken backlight driver, which overwrites the > intel backlight - for once it's not i915.ko's fault ;-) For a > workaround either disable the acpi backlight with > acpi_backlight=vendor (iirc) kernel option or teach the X driver that > you want a different backlight driver in the xorg.conf (Option > "Backlight" "intel_backlight" should do the trick). > -Daniel > -- > Daniel Vetter > Software Engineer, Intel Corporation > +41 (0) 79 365 57 48 - http://blog.ffwll.ch >
