Bug 26915

Summary:

xf86-video-ati + KMS TV-out PAL stripes

Product:

DRI

Reporter:

Da Fox <da.fox.mail>

Component:

DRM/Radeon

Assignee:

Default DRI bug account <dri-devel>

Status:

RESOLVED FIXED

QA Contact:

Xorg Project Team <xorg-team>

Severity:

normal

Priority:

medium

CC:

sandin

Version:

DRI git

Hardware:

x86 (IA32)

OS:

Linux (All)

Whiteboard:

i915 platform:

i915 features:

Attachments:

Description	Flags
fix pal issues	none

Description Da Fox 2010-03-05 12:54:49 UTC

Using current xf86-video-ati GIT, xorg-server-1.7.5 and kernel 2.6.33 with KMS default on I get strange artifacts when using PAL mode. What I see are horizontal lines (bands) from the left of the screen all the way to the right. They stay fixed in position, perfectly horizontal and are a few pixels tall (something like 4 or 5 pixels or so at a resolution of 800x600). Within a line the image is brighter/darker than it is supposed to be.
The effect of this is very similar to this [http://lions-wing.net/lessons/win-manage/xfce-1.png] image, if one assumes that the background is supposed to be a single, solid color blue. Only on the tv-out the effect is more pronounced and affects the complete output, not just the background.

Comment 1 Da Fox 2010-03-06 05:07:44 UTC

Using radeon-tool to dump some registers I've been able to identify which registers cause this change. In my case the following three registers seem to be important: TV_Y_FALL_CNTL, TV_Y_RISE_CNTL and TV_Y_SAW_TOOTH_CNTL.

The settings for these registers using current 6.12-branch are:
---8<---------
TV_Y_FALL_CNTL      (0858)      0x80030440 (-2147285952)
TV_Y_RISE_CNTL      (085c)      0x00012bc0 (76736)
TV_Y_SAW_TOOTH_CNTL (0860)      0x10002425 (268444709)
--->8---------

The settings for these registers using current master are:
---8<---------
TV_Y_FALL_CNTL      (0858)      0x00010880 (67712)
TV_Y_RISE_CNTL      (085c)      0x00013780 (79744)
TV_Y_SAW_TOOTH_CNTL (0860)      0x2000484b (536889419)
--->8---------

All three settings are important, but TV_Y_SAW_TOOTH_CNTL is the most important. Setting just TV_Y_SAW_TOOTH_CNTL to the setting of 6.12-branch removes the lines and gives a clean image. The image however is too bright (over-bright).
Setting TV_Y_FALL_CNTL and TV_Y_RISE_CNTL to the values of 6.12-branch reduces the brightness to normal levels, one 'step' of brightness for each setting.

Comment 2 Alex Deucher 2010-03-06 06:47:53 UTC

fix component.  this is a radeon drm bug.

Comment 3 Alex Deucher 2010-03-06 06:49:43 UTC

Created attachment 33809 [details] [review]
fix pal issues

Does this patch fix it?

Comment 4 Da Fox 2010-03-06 07:07:53 UTC

(In reply to comment #3)
> Created an attachment (id=33809) [details]
> fix pal issues
> 
> Does this patch fix it?
> 

Yes, that patch fixes the issue for me, thanks!
This bug may be closed now :)

Comment 5 Alex Deucher 2010-03-06 07:30:07 UTC

patch sent to Dave.

Comment 6 Martin Louda 2010-07-10 04:36:12 UTC

I'm having the same problem with current (2.6.34.1) kernel. Is there a chance the fix will hit kernel git tree?

Comment 7 Alex Deucher 2010-07-10 06:54:58 UTC

(In reply to comment #6)
> I'm having the same problem with current (2.6.34.1) kernel. Is there a chance
> the fix will hit kernel git tree?

It's already upstream.  What chip do you have?  This fix only applies to r1xx-r4xx asics.

Comment 8 Martin Louda 2010-07-10 08:18:26 UTC

(In reply to comment #7)
> It's already upstream.  What chip do you have?  This fix only applies to
> r1xx-r4xx asics.

I have rv280 (radeon 9200se), just switched to KMS so I've not experienced it before. I've checked this "flicker_removal" patch was not applied to mainline.

Comment 9 Alex Deucher 2010-07-12 08:54:22 UTC

I sent it out, but it looks like it must have slipped through the cracks and never got sent on to Linus.  I'll resend.

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