Bug#656015: [2.6.39 -> 3.0 regression] Monitor EDID not recognized by Linux kernel 3.x on AMD A6 CPU

[Jonathan Nieder <jrnieder@gmail.com>]

# regression
severity 656015 important
found 656015 linux-2.6/3.0.0-1
found 656015 linux-2.6/3.2~rc7-1~experimental.1
found 656015 linux-2.6/3.2.1-2
quit

Hi Grigor,

Grigor Gatchev wrote:

> After upgrading kernel from 2.6.39 to 3.0.0, monitor gets switched off
> during kernel boot. Otherwise all is OK (I can ssh in, etc).
>
> The following lines are found in the syslog:
>
> [drm] Radeon display connector HDMI-A-1: No monitor connected or invalid EDID
> [drm] Radeon display connector VGA-1: No monitor connected or invalid EDID
>
> The bug persists also in kernels 3.1.0, 3.1.0-1 and 3.2.0-rc7.
> Kernels up to 2.6.39 incl. work fine.
>
> Tested with several different monitors (all connected to the VGA port).

Thanks.  Interesting.

Please report this upstream at http://bugs.freedesktop.org/, product DRI,
component DRM/Radeon, and let us know the bug number so we can track
it.  Be sure to attach full "dmesg" output from booting an affected
kernel, and Xorg.0.log if applicable.

Hope that helps,
Jonathan