Bug 10436

Summary: Shearing on VGA outputs (DVI fine) with radeon driver on a RV100
Product: xorg Reporter: Tim Yamin <plasm>
Component: Driver/RadeonAssignee: xf86-video-ati maintainers <xorg-driver-ati>
Status: RESOLVED FIXED QA Contact: Xorg Project Team <xorg-team>
Severity: normal    
Priority: medium    
Version: unspecified   
Hardware: IA64 (Itanium)   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:
Attachments:
Description Flags
xorg.conf
none
Log (with VESA, working)
none
Log (with radeon) none

Description Tim Yamin 2007-03-27 16:04:23 UTC 
Hello,

When running startx so the standard session with twm and the thatched background is displayed what I can best describe as shearing occurs in the background. The output is crystal clear when using DVI but exhibits this issue when using the VGA port or a DVI->VGA converter. Using the vesa driver, this problem does not appear on the VGA port. If while I get the shearing I run something like dmesg in the xterm it looks like there is a problem with the vertical sync and darker stripes appear and then disappear temporarily while xterm is scrolling text... So I'm guessing the problem is with programming the DAC somewhere...

I'm attaching logs of X.Org running with radeon and with vesa. The config for the same is both, I just changed driver from radeon to vesa. The HorizSync/VertRefresh is there only to force the vesa driver into 1280x1024 (for some reason it otherwise goes into 640x480); it has no effect on the radeon driver's output.

From lspci (problem happens with both cards):

06:02.0 VGA compatible controller: ATI Technologies Inc Radeon RV100 QY [Radeon 7000/VE]
07:01.0 VGA compatible controller: ATI Technologies Inc Radeon RV100 QY [Radeon 7000/VE]

Thanks!
Comment 1 Tim Yamin 2007-03-27 16:04:58 UTC 
Created attachment 9329 [details]
xorg.conf
Comment 2 Tim Yamin 2007-03-27 16:05:31 UTC 
Created attachment 9330 [details]
Log (with VESA, working)
Comment 3 Tim Yamin 2007-03-27 16:05:58 UTC 
Created attachment 9331 [details]
Log (with radeon)
Comment 4 Michel Dänzer 2007-03-28 09:47:58 UTC 
The radeon log file isn't consistent with the config file; it shows two screen sections used. Please clarify this.

Also, does this happen with depth 16 and/or lower resolutions?
Comment 5 Tim Yamin 2007-03-28 13:40:27 UTC 
Happens regardless of how many screens are used and the same for both cards (although DVI on both is fine). It's better when used in depth 16 with the radeon driver but still noticeable (although less so).
Comment 6 Alex Deucher 2007-08-31 08:25:09 UTC 
does this still happen with the latest version of the ati driver from git?
Comment 7 Benjamin Close 2008-01-11 02:39:09 UTC 
Bugzilla Upgrade Mass Bug Change

NEEDSINFO state was removed in Bugzilla 3.x, reopening any bugs previously listed as NEEDSINFO.

  - benjsc
    fd.o Wrangler
Comment 8 Alex Deucher 2008-01-11 12:02:21 UTC 
I believe this was fixed in git a while ago (im-proper program of tvdac adj).  Please test a more recent version of the ati driver.  Please re-open if the problem persists.
Comment 9 Tim Yamin 2008-02-14 19:56:41 UTC 
Just to update the bug: in the end this was resolved and the culprit was a faulty VGA cable which didn't pass through the I2C data from the monitor correctly, so the refresh rate wasn't getting set to the one it should have been set to. Many thanks to Alex for taking the time to help diagnose the problem, much appreciated!

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