[Intel-gfx] [bisected] offset display bug in i915

[Jon Masters]

Hi Chris,

The following patch that you recently committed breaks my ASUS Eee PC
1015PEM by causing the display to be offset by about 1 inch (a few
centimeters) when the mode is (re)set during boot. I previously posted
both photographs and video of the problem in another "PROBLEM" thread.

Here is the offending commit found through bisection:

219adae138513bae20b256f1946b9cb3b75ca05c is the first bad commit
commit 219adae138513bae20b256f1946b9cb3b75ca05c
Author: Chris Wilson <chris at chris-wilson.co.uk>
Date:   Thu Sep 16 23:05:10 2010 +0100

    drm/i915: Cache LVDS EDID
    
    We assume that the panel is permenantly connected and that the EDID
    data is consistent from boot, so simply cache the whole EDID for the
    panel.
    
    Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>

I'll look at the patch. Either the EDID is *not* consistent (in which
case, why are we not seeing other bugs like this?) or there is something
specific to this system or panel used.

Jon.