asus-ul30 team mailing list archive

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Hey Brian,

On 21.05.2010 21:01 Brian Neltner wrote:
> Thanks for the suggestions.

you're welcome.

> I used the HDMI output with a TV to get 1920x1080 resolution, so I agree
> that it's not the video memory.
> 
> On my old, old linux system I would manually enter the available
> resolutions in my xorg.conf file; the monitor is definitely capable of
> 1280x1024 resolution, both according to my memory of using it with
> ancient versions of debian and ubuntu as well as from reading the
> technical specifications for the monitor online (Samsung SyncMaster
> 930B).
> 
> I have attached the errors produced by get-edid as Moritz suggested. I'm
> not sure how to read it, but I suspect this is the interesting section:

Correct, that's the interesting part.

> =======
> VBE/DDC service about to be called
>         Read EDID
> 
>         Performing real mode VBE call
>         Interrupt 0x10 ax=0x4f15 bx=0x1 cx=0x0
>         Function supported
>         Call failed
> 
> The EDID data should not be trusted as the VBE call failed
> EDID claims 19 more blocks left
> EDID blocks left is wrong.
> Your EDID is probably invalid.
> =======

read-edid and thus your X server is unable to retrieve EDID data from
one of your connected screens - most likely the SyncMaster 930B. You can
verify which screens' EDID cannot be determined by piping the read-edid
output through parse-edid: sudo read-edid | parse-edid
One screens' model and supported resultions will show, the others'
won't, or will look generic.

EDID data is some kind of self representation stored on a small
read-only memory chip found on most displays / monitors. It's a way for
the screen to report back about its make and model and supported modes
to the operating system.

If the operating system is unable to determine the supported modes of
the external devices then it starts guessing and can be overly
conservative in what it offers to support. It can be wrong then, too
(such as for the aspect ratio).

> I next tried looking at the firmware, which gave me the lshal.output
> file. I'm afraid that I don't know quite what this information means,
> but it looks like it may be the same bug reported by Moritz earlier. So,
> here's a confirmed on the bug existing.

The output generated by this command provides us with information on the
BIOS (firmware) version installed on your system and the kernel version
you are/were running.

You have BIOS version 212 installed, a version which appears to cause
some trouble with EDID data retrieval form external screens. You have
now a couple options to fix the resolution of your external monitor:

* (somehow) get your hands on a readymade SyncMaster 930B EDID file and
  install it on your xorg.conf using the CustomEDID option

* downgrade to BIOS v211

* downgrade to BIOS v211, create an EDID file by yourself
  (using something like sudo get-edid 1>sm930b.edid 2>/dev/null),
  then re-upgrade to BIOS v212 (or newer) and do as in the first
  suggestion

Moritz