Re: Monitor's EDID not recognised

From: Jeremy Murphy <jeremy.william.murphy-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
To: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
Cc: i2c-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org
Subject: Re: Monitor's EDID not recognised
Date: Sat, 8 Mar 2008 00:39:55 +1100	[thread overview]
Message-ID: <200803080039.55332.jeremy.william.murphy@gmail.com> (raw)
In-Reply-To: <20080307131120.4891f78e-ig7AzVSIIG7kN2dkZ6Wm7A@public.gmane.org>

On Fri, 7 Mar 2008 11:11:20 pm Jean Delvare wrote:
> On Fri, 7 Mar 2008 22:37:36 +1100, Jeremy Murphy wrote:
> >
> > I'm using nvidia's binary driver v169.07, and yes, the nvidia I2C buses
> > are there.  i2cdetect -l:
> >
> > i2c-3   i2c             NVIDIA i2c adapter                      I2C
> > adapter i2c-2   i2c             NVIDIA i2c adapter                     
> > I2C adapter i2c-1   i2c             NVIDIA i2c adapter                   
> >   I2C adapter i2c-0   smbus           SMBus I801 adapter at 0400         
> >     SMBus adapter
> >
> > However, decode-edid.pl and ddcmon both report that an EDID EEPROM is not
> > found.
>
> Please provide the output of:

I've just learnt that a number of people could no longer access their EDID 
after upgrading their nvidia driver to the 100.* series.  I downgraded to 
96.43.01 and now their is _something_ on the I2C nvidia bus 1, but it's not 
pretty.

These following results are inconsistent, which I'm guessing is not a good 
sign.  They vary somewhat between each call but they always have a similar 
pattern (row+col).

> i2cdetect 1

This is with eeprom loaded:

     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f
10: 10 11 12 13 14 15 16 17 18 19 1a 1b 1c -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 3f
40: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f
50: 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f
60: 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f
70: 70 71 72 73 74 75 76 77

This is without:

     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- 0b 0c 0d 0e 0f
10: 10 11 12 13 14 15 16 -- -- -- -- -- -- -- -- --
20: -- -- -- -- 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f
30: 30 31 32 33 34 35 36 37 38 39 3a 3b 3c 3d 3e 3f
40: 40 41 42 43 44 -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- 5a 5b 5c 5d 5e 5f
60: 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f
70: 70 71 72 73 74 75 76 77

At a guess, I'd say this is garbage?

> i2cdetect 2
> i2cdetect 3

Both empty.

> Either there is no EDID EEPROM connected at all (some monitors don't
> have them, in particular older models) or it has a format different
> from what the scripts expect.
>
> If anything shows up at 0x50 with i2cdetect, please provide a dump
> using i2cdump (rmmod eeprom first.)

This is the output of i2cdump 1 0x50:

     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef
00: 3f XX XX XX XX XX XX XX XX XX XX 00 00 00 00 00    ?XXXXXXXXXX.....
10: 00 00 00 00 XX XX XX XX XX XX XX XX XX XX 00 00    ....XXXXXXXXXX..
20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
30: 00 00 00 00 00 XX XX XX XX XX XX XX XX XX 00 00    .....XXXXXXXXX..
40: 00 00 00 00 00 00 00 00 XX XX XX XX XX 00 00 00    ........XXXXX...
50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
60: 00 00 00 00 00 00 00 00 00 00 00 XX XX XX XX XX    ...........XXXXX
70: XX XX XX XX XX XX 00 00 00 00 00 00 00 00 00 00    XXXXXX..........
80: 00 00 XX XX XX XX XX XX XX XX 00 00 00 00 00 00    ..XXXXXXXX......
90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
a0: XX 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    X...............
b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
c0: 00 00 00 00 XX XX XX XX XX XX XX XX XX XX XX 00    ....XXXXXXXXXXX.
d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
f0: 00 00 00 00 00 00 XX XX XX XX XX XX XX XX XX XX    ......XXXXXXXXXX

I presume the monitor has an EDID because the brochure says that it supports 
DDC-2B and DDC-2Bi, and it's relatively recent as far as CRTs go.  Thanks for 
your help, cheers.

Jeremy

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