[Mesa-users] Flickering with Intel i7-5700 (HD 5600) and Samsung 156HL01-102 panel

[Albert Freeman]

On 11 November 2015 at 07:21, Jordi Salvat i Alabart
<jordi.salvat.i.alabart at gmail.com> wrote:
> Thanks! I'll try this as soon as I can (probably over the weekend) and
> report back.
>
> Regards,
>
> Jordi
>
> El dia 10/11/2015 2:27 p. m., "Albert Freeman" <albertwdfreeman at gmail.com>
> va escriure:
>
>> On 10 November 2015 at 13:10, Albert Freeman <albertwdfreeman at gmail.com>
>> wrote:
>> > On 8 November 2015 at 19:05, Jordi Salvat i Alabart
>> > <jordi.salvat.i.alabart at gmail.com> wrote:
>> >> Noone? Not even a hint on where I could ask for help?
>> >>
>> >> :'-(
>> >>
>> >>
>> >>
>> >> 2015-10-26 0:18 GMT+01:00 Jordi Salvat i Alabart
>> >> <jordi.salvat.i.alabart at gmail.com>:
>> >>>
>> >>> Hi,
>> >>>
>> >>> My new MSI PE60 2QE laptop mounts an Intel i7-5700HQ, which carries
>> >>> the
>> >>> Integrated Graphics Chipset 5600, and a Samsung 156HL01-102 panel.
>> >>>
>> >>> The display works perfectly when I boot with the "nomodeset" parameter
>> >>> in
>> >>> the kernel command line -- but then I'm forced to use the framebuffer
>> >>> driver, which doesn't allow multiple monitors.
>> >>>
>> >>> With KMS enabled (by removing the "nomodeset" parameter), X starts
>> >>> correctly with the "intel" driver and I can use multiple monitors, but
>> >>> the
>> >>> laptop's panel shows an irregular flicker, ranging from occasional
>> >>> flickering horizontal black lines (which are really annoying) to a
>> >>> constant
>> >>> flashing & flickering making the display all but unusable.
>> >>>
>> >>> The flickering and flashing is less noticeable, but still there, in
>> >>> the
>> >>> text-mode VTs, even if I never start X. So the problem has to be in
>> >>> the
>> >>> kernel or modules, not in the X drivers.
>> >>>
>> >>> External monitors connected to the DP or HDMI ports don't show any
>> >>> flickering.
>> >>>
>> >>> Things I have tried (among many others I've discovered were
>> >>> irrelevant):
>> >>>
>> >>> Setting a number different video modes using xrandr
>> >>> Booting with Kernel 3.19.0.25 with i915.enable_IPS=0 as suggested
>> >>> here:
>> >>> Screen flickering on Ubuntu Gnome 14.04 - 4K resolution
>> >>> Booting with i915.powersave=0
>> >>> Booting with acpi_osi=Linux
>> >>> Upgrading to Ubuntu Vivid Vervet (kernel 3.19.0 with a backported i915
>> >>> module)
>> >>> Upgrading to Ubuntu Willy Werewolf (kernel 4.2.0)
>> >>>
>> >>> None of these have helped.
>> >>>
>> >>> I'm attaching kern.log for a full boot sequence with drm.debug=0xf.
>> >>>
>> >>> What steps can you recommend to try to diagnose and solve this
>> >>> problem?
>> >>>
>> >>> Thanks a lot for your help,
>> >>>
>> >>> Jordi
>> >>>
>> >>
>> >>
>> >> _______________________________________________
>> >> mesa-users mailing list
>> >> mesa-users at lists.freedesktop.org
>> >> http://lists.freedesktop.org/mailman/listinfo/mesa-users
>> >>
>> > Does this solve the issue (it solves a issue with your monitor) (it is
>> > applied ontop of the latest linus kernel tree at time of writing):
>> > diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
>> > index 05bb731..44c9422 100644
>> > --- a/drivers/gpu/drm/drm_edid.c
>> > +++ b/drivers/gpu/drm/drm_edid.c
>> > @@ -139,6 +139,9 @@ static struct edid_quirk {
>> >
>> >         /* Panel in Samsung NP700G7A-S01PL notebook reports 6bpc */
>> >         { "SEC", 0xd033, EDID_QUIRK_FORCE_8BPC },
>> > +
>> > +       /* Panel in Samsung 156HL01-102 display (for notebook) reports
>> > 6bpc instead of 8bpc */
>> > +       { "SDC", 0x324c, EDID_QUIRK_FORCE_8BPC },
>> >  };
>> >
>> >  /*
>> >
>> >
>> >
>> > !!!OR!!! Since the DRM is trying to force part of your monitor into 36
>> > bit mode, maybe this:
>> >
>> >
>> >
>> > diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
>> > index 05bb731..44c9422 100644
>> > --- a/drivers/gpu/drm/drm_edid.c
>> > +++ b/drivers/gpu/drm/drm_edid.c
>> > @@ -139,6 +139,9 @@ static struct edid_quirk {
>> >
>> >         /* Panel in Samsung NP700G7A-S01PL notebook reports 6bpc */
>> >         { "SEC", 0xd033, EDID_QUIRK_FORCE_8BPC },
>> > +
>> > +       /* Panel in Samsung 156HL01-102 display (for notebook) reports
>> > 6bpc instead of 12bpc */
>> > +       { "SDC", 0x324c, EDID_QUIRK_FORCE_12BPC },
>> >  };
>> >
>> >  /*
>> Sorry those patches don't apply properly, here are ones that do
After looking at intel drm driver code more carefully, don't use the
12 bpc one (12 * 3 == 36). The intel drm driver seems to first
generate certain values based on your gpu model. It then reduces it
based on display stuff (i.e. when I made the 12bpc version of the
patch I was looking at the intial value based on gpu model). I don't
think your display is capable of 36 bit color (12bpc) as the internet
says it only has 95% sRGB (e.g. high end consumer monitor, but not
perfect). 36bit is only for photographers and people producing
movies/game textures/game environments and other special high end
environments. Movies and games and practically every picture on the
internet is sRGB which is fully supported by 8 bit stuff. So cd to the
kernel source directory and execute git apply 8bit (with the 8bit
"patch in the same folder)