[lm-sensors] sensors-detect changed screen's vertical rate

Jean Delvare khali at linux-fr.org
Sat Apr 7 13:17:02 CEST 2012

On Sat, 7 Apr 2012 12:51:14 +0300, Numan DEMİRDÖĞEN wrote:
> 2012/4/7 Jean Delvare <khali at linux-fr.org>:
> > On Sat, 7 Apr 2012 11:24:15 +0300, Numan DEMİRDÖĞEN wrote:
> >> I gave related commands and after that made a cold boot but resolution
> >> did not changed.
> >> New i2cdump: http://pastebin.com/KExUrapp
> >
> > Hmm. I'm afraid I am somewhat out of ideas. I just can't get why you
> > would be able to write at some offsets and not others :( Unfortunately
> > the critical one here is 0x3b.
> >
> > One trick we can try is writing words instead of bytes, but honestly
> > the hope is rather low that it will work any better:
> >
> > # i2cset -y 2 0x50 0x3a 0x2050 w
> > # i2cset -y 2 0x50 0x3e 0x3010 w
> As you said, it did not take an effect on it.
> I really appreciate your effort, thank you very much.
> I will try to upgrade BIOS. If it solves the issue, I will feed back.

Hm, OK :( Meanwhile I had one more idea. From your original post it seems
that you have enabled option hw_i2c of the radeon driver:

> i2c-0   i2c             Radeon i2c bit bus DVI_DDC      I2C adapter
> i2c-1   i2c             Radeon i2c bit bus VGA_DDC      I2C adapter
> i2c-2   i2c             Radeon i2c hw bus MM_I2C        I2C adapter
> i2c-3   i2c             Radeon i2c bit bus MONID        I2C adapter

i2c-2 is precisely the I2C bus where your EDID is and where the problem
happened. AFAIK hw_i2c is off by default, so please check why and how
it was enabled. Then you may try to turn if off to force software
operation of the I2C bus (i2cdetect -l should show that), and then do
the i2cset commands again and see if it works. Again my hope level is
low but I think it is worth trying.

Jean Delvare

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