Disabling monitors with bad EDIDs?!?!

[Dave Airlie]

On Sun, Sep 19, 2010 at 7:43 PM, Richard Hughes <hughsient at gmail.com> wrote:
> In all new kernels my external HP LP2480zx display is disabled, with
> the following kernel message:
>
> [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 69
>
> I'm sure the drm layer didn't used to block monitors with bad EDIDs,
> as my monitor has worked reliably for ages now. Now it's effectively a
> glorified $3000 paperweight in Fedora 14.

I'd be interested in checking if your EDID has somehow been corrupted.

if its an expensive monitor it might be smart, power down the monitor,
unplug all cables (power + video),
leave it, and reconnect everything.

Its important to disconnect all cables at one time, since the EDID
chip is powered from VGA/DVI cables as well as monitor power.

you can also boot with video= option to force a mode.

Dave.