Bug 21413

Summary: Screen blanks after latest pll changes in Git
Product: xorg Reporter: Rafael Monica <monraaf>
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: git   
Hardware: Other   
OS: All   
Whiteboard:
i915 platform: i915 features:
Attachments:
Description Flags
Xorg log none

Description Rafael Monica 2009-04-26 05:50:27 UTC 
Created attachment 25149 [details] [review]
Xorg log

I have a Samsung 215TW monitor connected to the DVI output of a radeon HD 3200 IGP, all was working well till the recent changes to the pll code in git master.

Now I have random screen blanking and random noise in the picture. The screen blanking is at it's worst when playing a 720p movie, then the screen will blank up to several times a minute.

The offending commit:

commit 24e4b73b4fbbb2c790e6120ede3caaa4e7e58359
Author: Alex Deucher <alexdeucher@gmail.com>
Date:   Wed Apr 22 11:42:18 2009 -0400

radeon pll: add support for fractional feedback divs


Differences in the Xorg.0.log before(-) and after the commit(+).

 freq: 146250000
-best_freq: 146243000
-best_feedback_div: 817
-best_ref_div: 10
-best_post_div: 8
+best_freq: 146249974
+best_feedback_div: 786
+best_frac_feedback_div: 4
+best_ref_div: 11
+best_post_div: 7
 (II) RADEON(0): crtc(0) Clock: mode 146250, PLL 146240
-(II) RADEON(0): crtc(0) PLL  : refdiv 10, fbdiv 0x331(817), pdiv 8
+(II) RADEON(0): crtc(0) PLL  : refdiv 11, fbdiv 0x312(786), fracfbdiv 4, pdiv 7
Comment 1 Alex Deucher 2009-04-27 11:24:42 UTC 
disabled for now:
abd565ae71d9844d5afcd658628ca7778ce26ab1
Comment 2 Alex Deucher 2009-06-11 09:41:16 UTC 
I've incorporated Tom's patch (bug 22229) into xf86-video-ati git master.  Please test and let me know if you have any problems.
Comment 3 Rafael Monica 2009-06-11 12:59:54 UTC 
With the latest git it's broken again. 

Working situation: best_freq: 146243000
Does not work with best_freq: 146249974

As best_freq: 146249974 is lower than freq: 146250000, the patch doesn't do anything for me.
Comment 4 Alex Deucher 2009-06-11 13:10:50 UTC 
Ok.  I've only enabled the code on rs6xx chips for now.
808c90a24c48da7fa97e15e2f12be5bb8fd8cc96

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