Bug 23726 - Wrong resolution on Dell 2408WFP
Summary: Wrong resolution on Dell 2408WFP
Status: RESOLVED NOTOURBUG
Alias: None
Product: xorg
Classification: Unclassified
Component: Driver/Radeon (show other bugs)
Version: 7.4 (2008.09)
Hardware: x86 (IA32) Linux (All)
: medium normal
Assignee: xf86-video-ati maintainers
QA Contact: Xorg Project Team
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2009-09-05 05:04 UTC by Martin
Modified: 2009-09-07 05:31 UTC (History)
1 user (show)

See Also:
i915 platform:
i915 features:


Attachments
output of xrandr (981 bytes, patch)
2009-09-05 05:05 UTC, Martin
no flags Details | Splinter Review
output of ddcprobe (851 bytes, application/octet-stream)
2009-09-05 05:05 UTC, Martin
no flags Details
video bios (63.50 KB, application/octet-stream)
2009-09-05 05:05 UTC, Martin
no flags Details
xorg.log (101.61 KB, text/plain)
2009-09-07 05:26 UTC, Martin
no flags Details

Description Martin 2009-09-05 05:04:18 UTC
I have connected a Dell 2408WFP monitor with a native resolution of 1920x1200  via DVI on my laptop. However xorg autoconfigures it at 1152x864. I can set it to 1920x1200 with xrandr but I think xorg should do that by default.

I using Ubuntu 9.10 karmic koala:
xserver-xorg 7.4+3ubuntu5
xserver-xorg-core 1.6.3-1ubuntu5
xserver-xorg-video-radeon 6.12.99+git20090825.fc74e119-0ubuntu1

I attached my Xorg.log, the output of xrandr and ddcprobe as well as my video bios rom.
Comment 1 Martin 2009-09-05 05:05:06 UTC
Created attachment 29245 [details] [review]
output of xrandr
Comment 2 Martin 2009-09-05 05:05:19 UTC
Created attachment 29246 [details]
output of ddcprobe
Comment 3 Martin 2009-09-05 05:05:54 UTC
Created attachment 29247 [details]
video bios
Comment 4 Alex Deucher 2009-09-05 07:47:22 UTC
This isn't a driver bug.  It's the default behavior of the xserver.  By default, unless you specify otherwise, the xserver attempts to set all connected monitors to the same mode (whatever mode is common between all monitors if possible).  If you want different behavior you need to specify preferred modes in your xorg.conf.  See this page for more information:
http://wiki.debian.org/XStrikeForce/HowToRandR12
Comment 5 Martin 2009-09-05 09:10:57 UTC
Thank you for this information. Setting the option "PreferredMode" seems to work but just for my understanding: I'm still wondering why by default 1152x864 is choosen, as
a) the highest common resolution of both displays is 1280x1024
b) the laptop is on a docking station and the lid is closed. The external monitor is the only one so I would expect Xorg to set it to its native resolution without having to set it in xorg.conf (I didn't have an xorg.conf at all before)
Comment 6 Alex Deucher 2009-09-05 12:41:37 UTC
Please attach your xorg log.
Comment 7 Alex Deucher 2009-09-05 12:45:26 UTC
(In reply to comment #5)
> Thank you for this information. Setting the option "PreferredMode" seems to
> work but just for my understanding: I'm still wondering why by default 1152x864
> is choosen, as
> a) the highest common resolution of both displays is 1280x1024

Need to see the log to see why the xserver picked that mode.  It may be the largest mode with the same aspect ratio as the preferred mode.

> b) the laptop is on a docking station and the lid is closed. The external
> monitor is the only one so I would expect Xorg to set it to its native
> resolution without having to set it in xorg.conf (I didn't have an xorg.conf at
> all before)
> 

The driver doesn't handle lid events.  At the moment they are handled by acpi so you'd have to set up an event handler to deal with them and do the appropriate thing via xrandr.
Comment 8 Martin 2009-09-07 05:26:43 UTC
Created attachment 29299 [details]
xorg.log
Comment 9 Martin 2009-09-07 05:31:42 UTC
(In reply to comment #7)
> (In reply to comment #5)
> > b) the laptop is on a docking station and the lid is closed. The external
> > monitor is the only one so I would expect Xorg to set it to its native
> > resolution without having to set it in xorg.conf

> The driver doesn't handle lid events.  At the moment they are handled by acpi
> so you'd have to set up an event handler to deal with them and do the
> appropriate thing via xrandr.

Well I think this is another issue. The lid is closed all the time since bootup, so there is no lid event. Doesn't the radeon driver notice that the internal display is turned off/closed?


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