Bug#622993: every 10s I get "[drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid ..."
Vincent Danjean wrote:
> For info, sometimes ago, I also add a problem with spurious
> "[drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid ..."
> Sorry, I do not remember from which exact kernel version it was. The
> problems occurs for a second screen on DVI output of a laptop. It was
> intermittent (ie most of the time, the EDID was correct but sometimes
> the EDID was read incorrectly and the output was disabled).
There was recently (v2.6.39-rc2~3^2~24) an interesting fix in the
| $ git show v2.6.39-rc2~3^2~24
| commit 4819d2e4310796c4e9eef674499af9b9caf36b5a
| Author: Chris Wilson <firstname.lastname@example.org>
| Date: Tue Mar 15 11:04:41 2011 +0000
| drm: Retry i2c transfer of EDID block after failure
| Usually EDID retrieval is fine. However, sometimes, especially when the
| machine is loaded, it fails, but succeeds after a few retries.
| Based on a patch by Michael Buesch.
| Reported-by: Michael Buesch <email@example.com>
| Signed-off-by: Chris Wilson <firstname.lastname@example.org>
| Reviewed-by: Alex Deucher <email@example.com>
| Signed-off-by: Dave Airlie <firstname.lastname@example.org>
So I'd be interested in results using the kernel from experimental if
you're willing. It would also be interesting to know approximately
when "sometimes ago" is --- one month? one year? five years?
> I "solved" this by adding
> options drm_kms_helper poll=N
Someone mentioned this workaround on lkml, too. I'm not so fond of
workarounds before fixes; they hide bugs. :)
Thanks, this seems useful.