Bug 19348

Summary: Radeon driver refuses mode advertised by monitor.
Product: xorg Reporter: Phil Armstrong <phil>
Component: Driver/RadeonAssignee: xf86-video-ati maintainers <xorg-driver-ati>
Status: RESOLVED INVALID QA Contact: Xorg Project Team <xorg-team>
Severity: normal    
Priority: medium    
Version: 7.4 (2008.09)   
Hardware: x86 (IA32)   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:
Attachments:
Description Flags
Working Xorg.0.log: note that the monitor 1920x1200 mode is rejected, but hand coded one with same values is fine!
none
xorg.conf none

Description Phil Armstrong 2008-12-31 07:57:20 UTC 
Created attachment 21591 [details] [review]
Working Xorg.0.log: note that the monitor 1920x1200 mode is rejected, but hand coded one with same values is fine!

The Radeon driver is unable to drive my nice new HP LP2475w at it's native resultion of 1920x1200 out of the box, because it rejects the mode settings in the Monitor EDID data. According to the logs:

  (II) RADEON(0): Not using default mode "1920x1200" (monitor doesn't support reduced blanking)

However, if I suck the preferred mode out with get-edid | parse-edid, and put that mode into the Monitor section of xorg.conf, then the mode is accepted by the driver & works perfectly.

I think this counts as a bug, although I'm not sure precisely who to blame!

I'm using the radeon driver & X version from Debian experiental. The radeon driver is fairly close to git head as of the end of Dec 2008. Xorg is release 7.4
Comment 1 Phil Armstrong 2008-12-31 07:57:51 UTC 
Created attachment 21592 [details] [review]
xorg.conf
Comment 2 Alex Deucher 2009-01-03 09:33:57 UTC 
The xserver, not the driver, handles the mode checking in question.  The xserver is rejecting the default 1920x1200 mode added by the xserver, not the one from the EDID.  The one from the EDID is added along with the modeline you added:

(II) RADEON(0): Printing probed modes for output DVI-0

your modeline:

(II) RADEON(0): Modeline "1920x1200R"x60.0  154.00  1920 1968 2000 2080  1200 1203 1209 1235 -hsync +vsync (74.0 kHz)

EDID mode:

(II) RADEON(0): Modeline "1920x1200"x60.0  154.00  1920 1968 2000 2080  1200 1203 1209 1235 +hsync -vsync (74.0 kHz)

Can you attach a log from when the xserver fails to start?
Comment 3 Alex Deucher 2009-11-11 10:46:15 UTC 
closing due to lack of feedback.

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