On Sat, 23 Aug 2014, Hans de Goede <hdegoede@xxxxxxxxxx> wrote: > Hi, > > On 08/22/2014 08:48 AM, Jani Nikula wrote: >> On Fri, 22 Aug 2014, Bertrik Sikken <bertrik@xxxxxxxxx> wrote: >>> On 19-8-2014 3:29, Jani Nikula wrote: >>>> On Tue, 19 Aug 2014, Bertrik Sikken <bertrik@xxxxxxxxx> wrote: >>>>>> On Sun, 17 Aug 2014, Bertrik Sikken <bertrik@xxxxxxxxx> wrote: >>>>>>> On 15-8-2014 3:43, Jani Nikula wrote: >>>>>>>> On Thu, 14 Aug 2014, Bertrik Sikken <bertrik@xxxxxxxxx> wrote: >>>>>>> >>>>>>>>> Attached is dmesg output from booting kernel 3.14-2 (debian unstable) >>>>>>>>> with drm.debug=0xe and the samsung_laptop module enabled, from my >>>>>>>>> Samsung N150plus netbook. >>>>>>>> >>>>>>>> Have you tried 3.15? >>>>>>> >>>>>>> I've built the v3.15 kernel (using the .config file from debian >>>>>>> unstable and doing make oldconfig). >>>>>>> >>>>>>> The backlight is at maximum brightness after boot and I can't control >>>>>>> it using the backlight buttons, nor by writing to >>>>>>> /sys/class/backlight/samsung/brightness >>>>>>> (say half the value or 1/10th of max_brightness) >>>>>>> >>>>>>> Backlight does work when writing >>>>>>> /sys/class/backlight/intel_backlight/brightness >>>>>> >>>>>> How about disabling samsung backlight module with 3.15? >>>>> >>>>> I'm not sure what you mean by that. >>>>> >>>>> As I understand it, there are three ways to control the backlight on this >>>>> netbook: using intel_backlight, samsung_laptop (using a "sabi" interface) >>>>> and acpi_video. >>>>> Backlight control using the samsung_laptop driver no longer seems to work >>>>> after the change. If I disable it (e.g. by blacklisting it), I expect it >>>>> to no longer work at all obviously. >>>>> >>>>> What do you want me to test exactly? >>>> >>>> If the intel_backlight interface works in 3.15, I presume the problem is >>>> that you have a non-functional samsung backlight interface that is >>>> preferred over intel_backlight by your userspace. >>> >>> I tested the intel_backlight interface in linux v3.15 with the samsung >>> backlight module blacklisted. The intel_backlight interface still works. >> >> I read that as, "I no longer have problems with backlight". > > No, just NO. This thread has "REGRESSION" in the subject for a reason, > userspace will prefer a firmware backlight interface over a raw backlight > interface, so the only way to get userspace to use the intel backlight > driver is to blacklist the samsung_laptop and acpi_video (Bertrik can you > confirm that acpi_video also is broken?) so that the intel one is the only > remaining. Fair enough. I'm going to need a bunch of attached files that will be awkward on the mailing list, so please file a new bug against DRM/Intel at [1]. Refer this mail thread, and attach the output of intel_reg_dumper (from intel-gpu-tools [2]) on a working and a non-working kernel. Also attach /sys/kernel/debug/dri/0/i915_opregion On the broken kernel, does the samsung backlight interface work *before* you've loaded i915.ko? Thanks, Jani. [1] https://bugs.freedesktop.org/enter_bug.cgi?product=DRI [2] http://cgit.freedesktop.org/xorg/app/intel-gpu-tools/ -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
