On Thu, 13 Feb 2014, Luis Ortega <luiorpe1@xxxxxx> wrote: > On Thu, Feb 13, 2014 at 05:24:23PM +0100, Luis Ortega wrote: >> > I dare say either your bisect went sour or you don't have 945GM. Please >> > verify your steps. >> >> Well, what can I say? I was careful when testing and the last kernel I compiled >> shows the problem. I can replay the bisection if needed but if I have to start >> all over again it's gonna take some time. I'm compiling in the netbook and took >> me day and a half to finish the process. >> >> In all honesty, along the way I met commit messages that I thought were more >> probable to introduce this regression. (backlight related) >> >> Also, here's the output of lspci: >> 00:00.0 Host bridge: Intel Corporation Mobile 945GSE Express Memory Controller Hub (rev 03) >> 00:02.0 VGA compatible controller: Intel Corporation Mobile 945GSE Express Integrated Graphics Controller (rev 03) >> 00:02.1 Display controller: Intel Corporation Mobile 945GM/GMS/GME, 943/940GML Express Integrated Graphics Controller (rev 03) >> >> > Please provide dmesg with drm.debug=0xe with 3.14-rc2. >> >> Care to explain a bit more before I recompile 3.14-rc2? Do I need to >> enable some particular debug option? How do I proceed for drm.debug=0xe? >> >> >> Luis >> > On Thu, Feb 13, 2014 at 05:04:23PM +0200, Jani Nikula wrote: >> > On Thu, 13 Feb 2014, Luis Ortega <luiorpe1@xxxxxx> wrote: >> > > Hi, testing 3.14-rc2 I noticed I could not adjust the brightness of the >> > > screen any longer. This problem is already present in 3.14-rc1. 3.13 works fine. >> > > >> > > My hardware is a netbook with intel atom and a 945GM graphics card. >> > > >> > > I bisected the problem down to the next commit: >> > >> > I dare say either your bisect went sour or you don't have 945GM. Please >> > verify your steps. >> > >> > Please provide dmesg with drm.debug=0xe with 3.14-rc2. >> > >> > BR, >> > Jani. >> > >> > > >> > > bc0bb9fd1c7810407ab810d204bbaecb255fddde is the first bad commit >> > > commit bc0bb9fd1c7810407ab810d204bbaecb255fddde >> > > Author: Jani Nikula <jani.nikula@xxxxxxxxx> >> > > Date: Thu Nov 14 12:14:29 2013 +0200 >> > > >> > > drm/i915: remove QUIRK_NO_PCH_PWM_ENABLE >> > > >> > > The quirk was added as what I'd say was a stopgap measure in >> > > >> > > commit e85843bec6c2ea7c10ec61238396891cc2b753a9 >> > > Author: Kamal Mostafa <kamal@xxxxxxxxxxxxx> >> > > Date: Fri Jul 19 15:02:01 2013 -0700 >> > > >> > > drm/i915: quirk no PCH_PWM_ENABLE for Dell XPS13 backlight >> > > >> > > without really digging into what was going on. >> > > >> > > Also, as mentioned in the related bug [1], having the quirk regressed >> > > some of the machines it was supposed to fix to begin with, and there >> > > were patches posted to disable the quirk on such machines [2]! >> > > >> > > The fact is, we do need the BLM_PCH_PWM_ENABLE bit set to have >> > > backlight. With the quirk, we've relied on BIOS to have set it, and our >> > > save/restore code to retain it. With the full backlight setup at enable, >> > > we have no place for things that rely on previous state. >> > > >> > > With the per platform hooks, we've also made a change in the PCH >> > > platform enable order: setting the backlight duty cycle between CPU and >> > > PCH PWM enable. Some experimenting and >> > > >> > > commit 770c12312ad617172b1a65b911d3e6564fc5aca8 >> > > Author: Takashi Iwai <tiwai@xxxxxxx> >> > > Date: Sat Aug 11 08:56:42 2012 +0200 >> > > >> > > drm/i915: Fix blank panel at reopening lid >> > > >> > > indicate that we can't set the backlight before enabling CPU PWM; the >> > > value just won't stick. But AFAICT we should do it before enabling the >> > > PCH PWM. >> > > >> > > Finally, any fallout we should fix properly, preferrably without quirks, >> > > and absolutely without quirks that rely on existing state. With the per >> > > platform hooks have much more flexibility to adjust the sequence as >> > > required by platforms. >> > > >> > > [1] https://bugzilla.kernel.org/show_bug.cgi?id=47941 >> > > [2] http://lkml.kernel.org/r/1378229848-29113-1-git-send-email-kamal@xxxxxxxxxxxxx >> > > >> > > Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> >> > > Reviewed-by: Imre Deak <imre.deak@xxxxxxxxx> >> > > Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx> >> > > >> > > >> > > Additionally, when I had narrowed the problem to around 11 commits all the >> > > resulting kernel I compiled made the screen blink and shake from left to right >> > > non-stop. In the -rc kernels this doesn't happen. Thought it was worth >> > > mentioning. >> > >> > >> > -- >> > Jani Nikula, Intel Open Source Technology Center > >> Please provide dmesg with drm.debug=0xe with 3.14-rc2. > > I've booted with the kernel args drm.debug=0xe log_buf_len=16M. > I've attached the following files for your inspection: > > dmesg.txt - dmesg output > lspci.txt - output of: su -c 'lspci -nn' > /var/log/Xorg.0.log > > Ask me if there is anything else I can do to help. It seems that it will be better to track this in bugzilla rather than the mailing lists. Please file a bug on DRM/Intel component at https://bugs.freedesktop.org/enter_bug.cgi?product=DRI. Attach these files. Also, please include the output of 'ls /sys/class/backlight'. The Xorg.0.log indicates you have a backlight device of "platform" type which should be preferred over the "raw" intel_backlight: > [ 29.333] (--) intel(0): found backlight control interface eeepc (type 'platform') If you try changing backlight using the sysfs under /sys/class/backlight/<interface> using 'sudo sh -c "echo N > brightness"' where N is a value between 0 and `cat max_brightness`, do the interfaces there work, intel_backlight in particular? Please include this information in the bug. Additionally, a register dump for both the working and non-working cases using tools/intel_reg_dumper from the intel-gpu-tools package might prove to be helpful. BR, Jani. -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
