[Intel-gfx] Intel eDP and fixed_mode probing/initialization

[Josh Litherland]

Hoping someone can point me in the right direction to understanding
how intel_connector->panel.fixed_mode gets probed, as it's referenced
in function "intel_dp_mode_valid" at drivers/gpu/drm/i915/intel_dp.c.

I am working with a panel hooked up via DSUB to a port that is
internally wired as eDP-1.  The kernel is correctly probing its
EDID-advertised preferred mode, 1360x768 at 60.  However, in the
above-named function, that mode is then being discarded with status
MODE_PANEL (exceeds panel dimensions).  After poking around a bit and
adding some debugging output, I've gotten as far as the above-named
function and found that fixed_mode is coming in to that function as
1280x800.  Trying to trace back farther than that I get a bit lost.

Thanks in advance if anyone can help me figure out where that spurious
mode limitation is coming from.

Incidentally, commenting out the checks against fixed_mode->hdisplay
and fixed_mode->vdisplay make the panel work correctly, but I'd like
to come at this from the other direction and find out why the probe
failed in the first place.

Thanks!

Kernel is 3.16.0-4-686-pae from Debian Jessie
Device is Intel Atom Processor Z36xxx/Z37xxx (8086:0f31)
Dmesg here, interesting bit starts around line 807:
     http://pastebin.com/kpeWW0iB

-- 
Josh Litherland (josh at temp123.org)