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Renan Birck

Member

From: Brazil

Registered: 2007-11-11

Posts: 401

Website

With KMS on Intel i965, no dual-head

Hello,

Without KMS I could use dual-head properly on my laptop Acer Aspire 7720, which has Intel i965 video chipset.
Now, with KMS and kernel 2.6.30, I can't anymore.

Steps:

- I plug the monitor into the VGA connector.
- I run 'xrandr --output VGA --right-of LVDS', which used to work. Nothing on the screen, however. I get this error in dmesg:

[drm:edid_is_valid] *ERROR* EDID checksum is invalid, remainder is 32
[drm:edid_is_valid] *ERROR* Raw EDID:
<3>00 ff ff ff ff ff ff 00 05 e3 62 a5 3e c0 0d 00  ..........b.>...
<3>04 0f 01 03 68 1e 17 82 2a d5 ed a0 5a 4a 98 24  ....h...*...ZJ.$
<3>16 4d 53 bf ee 00 61 40 61 4f 45 40 45 4f 31 40  .MS...a@aOE@EO1@
<3>a1 ff 01 01 01 01 64 19 00 40 41 00 26 30 18 88  ......d..@A.&0..
<3>36 00 30 e4 10 00 00 18 00 00 00 ff 00 54 35 43  6.0..........T5C
<3>53 35 31 41 39 30 31 31 38 32 00 00 00 fd 00 37  S51A901182.....7
<3>4b 1e 3f 08 00 0a 20 20 20 20 20 20 00 00 00 fc  K.?...      ....
<3>00 4c 4d 35 32 30 2f 4c 4d 35 32 30 41 0a 00 44  .LM520/LM520A..D

i915 0000:00:02.0: VGA-1: EDID invalid.
[drm:edid_is_valid] *ERROR* EDID checksum is invalid, remainder is 32
[drm:edid_is_valid] *ERROR* Raw EDID:
<3>00 ff ff ff ff ff ff 00 05 e3 62 a5 3e c0 0d 00  ..........b.>...
<3>04 0f 01 03 68 1e 17 82 2a d5 ed a0 5a 4a 98 24  ....h...*...ZJ.$
<3>16 4d 53 bf ee 00 61 40 61 4f 45 40 45 4f 31 40  .MS...a@aOE@EO1@
<3>a1 ff 01 01 01 01 64 19 00 40 41 00 26 30 18 88  ......d..@A.&0..
<3>36 00 30 e4 10 00 00 18 00 00 00 ff 00 54 35 43  6.0..........T5C
<3>53 35 31 41 39 30 31 31 38 32 00 00 00 fd 00 37  S51A901182.....7
<3>4b 1e 3f 08 00 0a 20 20 20 20 20 20 00 00 00 fc  K.?...      ....
<3>00 4c 4d 35 32 30 2f 4c 4d 35 32 30 41 0a 00 44  .LM520/LM520A..D

i915 0000:00:02.0: VGA-1: EDID invalid.

Is there some way to get the driver to ignore the EDID (which is invalid and seem to be causing problem) and get dual-head working (preferrably while keeping KMS)?

Thanks.

Thanks.

---

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habarnam

Member

From: Berlin, Germany

Registered: 2008-11-26

Posts: 26

Website

Re: With KMS on Intel i965, no dual-head

Hi Renan, I don't know how far you've made it with your problem and if maybe you solved it. I have similar issues on my system so I thought to share some of my experience:

I have a dual head desktop box which almost works. The difference is that I am using a well defined monitor setup and as such I followed this guide: Intel dualhead for a suitable xorg.conf. It made it almost work, but with the DVI monitor not being properly recognized by xrandr and not accepting a resolution higher than 1024x768. I circumvented this, by uncommenting the PreferredMode entries in xorg.conf.

However this doesn't actually work with KMS enabled - as the console is not using the correct resolution (I just removed i915.modeset=1 from the kernel's options). Still I can use UXA with X and the intel driver, which gives okaysh performance.

So, bottom line is, maybe you can overwrite the EDID settings by using a xorg.conf with PreferredMode for each of the monitors.

Last edited by habarnam (2009-08-08 11:44:43)