[Intel-gfx] i915 and 1440p display w/ corrupt EDID

[Mathias Burén]

On 27 September 2014 16:39, Mathias Burén <mathias.buren at gmail.com> wrote:
> On 26 September 2014 08:25, Jani Nikula <jani.nikula at linux.intel.com> wrote:
>> On Wed, 24 Sep 2014, Mathias Burén <mathias.buren at gmail.com> wrote:
>>> I've a 1440p display with a non-sufficient/corrupt EDID.
>>
>> Just to double check, you mean the display really is broken in this
>> regard, *not* that the driver is unable to read the EDID?
>
> I think the EDID is broken as I got this monitor working with a
> specific EDID file:
> http://learnitwithme.com/wordpress/wp-content/uploads/2012/05/edid-shimian.bin
> taken from this blog post on the subject: http://electron14.com/?p=342
>
>>
>> Does your monitor have other connections than HDMI? Can you try to see
>> if they produce a valid EDID? It may be possible to use that EDID for
>> HDMI using the EDID firmware mechanism.
>
> Sorry no, it only has a dual DVI input, nothing else. (no HDMI)
>
>>
>>> When I connect the display to the laptop via the docking station, the
>>> laptop detects that there is a display connected, but there are no
>>> modes available. I can add a mode like this:
>>
>> Have you tried without the dock to reduce the number of failure points?
>
> The laptop only has VGA and DP out unfortunately.
>
>>
>>> xrandr --newmode "2560x1440_60.0" 311.83 2560 2744 3024 3488 1440 1441
>>> 1444 1490 -HSync +Vsync
>>> xrandr --addmode HDMI3 2560x1440_60.0
>>>
>>> But I get an error when trying to use it: "xrandr: Configure crtc 1 failed".
>>>
>>> Does anyone have any tips on how to get the monitor working?
>>
>> Finally, dmesg with drm.debug=14 from boot to the problem, including the
>> above attempt with xrandr, might prove useful.
>>
>> BR,
>> Jani.
>>
>>
>> --
>> Jani Nikula, Intel Open Source Technology Center
>
> Some logs:
>
> cmdline: BOOT_IMAGE=/vmlinuz-3.17.0-997-lowlatency
> root=/dev/mapper/vg0-root ro quiet threadirqs fastboot logo.nologo
> elevator=deadline drm.debug=14
>
> $ xrandr
> xrandr: Output HDMI3 is not disconnected but has no modes
> Screen 0: minimum 320 x 200, current 1600 x 900, maximum 32767 x 32767
> LVDS1 connected primary 1600x900+0+0 (normal left inverted right x
> axis y axis) 310mm x 174mm
>    1600x900       60.0*+
>    1440x900       59.9
>    1360x768       59.8     60.0
>    1152x864       60.0
>    1024x768       60.0
>    800x600        60.3     56.2
>    640x480        59.9
> VGA1 disconnected (normal left inverted right x axis y axis)
> HDMI1 disconnected (normal left inverted right x axis y axis)
> DP1 disconnected (normal left inverted right x axis y axis)
> HDMI2 disconnected (normal left inverted right x axis y axis)
> HDMI3 connected (normal left inverted right x axis y axis)
> DP2 disconnected (normal left inverted right x axis y axis)
> DP3 disconnected (normal left inverted right x axis y axis)
> VIRTUAL1 disconnected (normal left inverted right x axis y axis)
>
> dmesg | cat drm: http://pastebin.com/n8GjZNjA
>
> Is there a way I can specify the Intel driver to use another EDID? By
> the way, if I connect this display under Windows 7 I would normally
> get a BSOD or it's not detected at all.
>
> Regards
> Mathias

Here's the attempt to use the EDID file via the sysfs interface:
http://pastebin.com/3brap4wB