strange edid issue

Angelo Dureghello angelo70 at
Thu Sep 12 14:30:09 PDT 2013

Dear all,

i am using radeon opensource driver in linux:

OpenGL vendor string: X.Org
OpenGL renderer string: Gallium 0.4 on AMD TURKS
OpenGL version string: 2.1 Mesa 9.2.0 (git-81e585f)
OpenGL shading language version string: 1.30
OpenGL extensions:

01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. 
[AMD/ATI] Turks XT [Radeon HD 6670/7670]

Acer AL2216W

Strangely, i had an edid issue (checksum error from kernel load) on DVI 
DVI channel was blank, only VGA channel was working.

I have electronic experience, so
- opened the monitor,
- de-soldered i2c eeprom,
- soldered to an eeprom programmer,
- read content,
- found a corrupted byte in the edid table, DVI channel
- corrected value, re-programmed the i2c, re-soldered on the monitor

Result: everything worked again properly.

After about 2 years, yesterday, happen again.
Found again a byte corrupted but in a different position.
Did same job as above.

Now monitor works again.

This issue with edid is very frequent, for different causes, but in 
these cases, non electronics get crazy and can't get out generally.

My question to you is:
Is possible the Radeon driver have some responsability, accidentally 
damaging a byte sometime ?
Is it more a monitor vulnerability ?

Many thanks

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