Kernel module radeon constantly reports about invalid EDID to /var/log/syslog and virtual consoles

Project:Trisquel
Component:Kernel/drivers
Category:bug report
Priority:normal
Assigned:upstream
Status:active
Description

I have an integrated Radeon 2100 card as part of the RS740 AMD chipset. The motherboard has only two physical connectors - VGA and DVI. It seems the driver is detecting a second DVI connector, that has no physical output.

There is an issue in the kernel module that causes it to constantly report that there is connected monitor to the second DVI (non-physical) connector, but it's data is wrong.

The error output is:

[ 4598.622287] [drm:radeon_dvi_detect] *ERROR* DVI-D-1: probed a monitor but no|invalid EDID
[ 4608.699708] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 152
[ 4608.699717] [drm:drm_edid_block_valid] *ERROR* Raw EDID:
[ 4608.699725] <3>1f 07 07 07 07 07 07 07 07 07 07 07 07 07 07 07  ................
[ 4608.699732] <3>07 07 07 07 07 07 07 07 07 07 07 07 07 07 07 07  ................
[ 4608.699738] <3>07 07 07 07 07 07 07 07 07 07 07 07 07 07 07 07  ................
[ 4608.699744] <3>07 07 07 07 07 07 07 07 07 07 07 07 07 07 07 07  ................
[ 4608.699749] <3>07 07 07 07 07 07 07 07 07 07 07 07 07 07 07 07  ................
[ 4608.699755] <3>07 07 07 07 07 07 07 07 07 07 07 07 07 07 07 07  ................
[ 4608.699761] <3>07 07 07 07 07 07 07 07 07 07 07 07 07 07 07 07  ................
[ 4608.699766] <3>07 07 07 07 07 07 07 07 07 07 07 07 07 07 07 07  ................

This is printed every few seconds in virtual consoles, /var/log/syslog, and the output of dmesg.

In a thread at Ubuntu forums a way to fix this is proposed, based on the information in the kernel module issue thread. The bit_test parameter of the i2c-algo-bit module should be set to 1 in a /etc/modprobe.d/ config file. This stops the error messages.

I've tested it and it works. This is the contents of the /etc/modprobe.d/i2c-algo-bit.conf file I've created:

options i2c-algo-bit bit_test=1

I don't know if anybody else is having this issue, but I think this should somehow be provided by Trisquel.

Mon, 04/02/2012 - 22:00
Assigned to:anonymous» upstream

Marking as assigned to upstream:

Ubuntu Bug #539851

I believe this is regarding the same bug.