Re: [.30-rc2 regression] garbled screen on video

[Justin Madru]

Eric Anholt wrote:
> On Thu, 2009-04-23 at 17:52 -0700, Justin Madru wrote:
>   
> > Hi everyone,
> >
> > Summary:
> > After playing a video for a little bit, the screen gets garbled. The 
> > only way to fix it is to
> > switch to a virtual console and then back. The screen is fixed but 
> > unfortunately only for
> > less than a few minuets and the screen gets corrupted again.
> >
> > Effected Version: 2.6.30-rc2+
> > Picture showing a corrupt screen: 
> > http://ecs.fullerton.edu/~cs351a15/badscreen.jpg
> >
> > My System:
> > Ubuntu 9.4 with 943/940GML Express Integrated Graphics Controller 
> > [8086:27a2]
> > UXA/GEM/DRI2 enable. Full info at 
> > http://jdserver.homelinux.org/bugreports/004/
> >
> > Syslog Messages:
> > None, but switching virtual consoles gives
> > [drm:i915_get_vblank_counter] *ERROR* trying to get vblank count for 
> > disabled pipe 0
> > But I think that is another bug introduced with .30-rc1.
> >     
>
> Interesting.  Could you open a bug at bugs.freedesktop.org against xorg,
> driver/intel, to be sure this doesn't get lost?
>
> However, I suspect that the commit in question isn't causing your issue,
> but is just when tiling got reenabled on your platform so you got to see
> other (likely userland) bugs.  To test, you could revert the patch you
> bisected to and just apply one of the hunks with a little tweak:
>
> diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c
> index 6be3f92..f27e523 100644
> --- a/drivers/gpu/drm/i915/i915_gem_tiling.c
> +++ b/drivers/gpu/drm/i915/i915_gem_tiling.c
> @@ -127,8 +129,8 @@ i915_gem_detect_bit_6_swizzle(struct drm_device *dev)
>  				swizzle_y = I915_BIT_6_SWIZZLE_9_11;
>  			} else {
>  				/* Bit 17 swizzling by the CPU in addition. */
> -				swizzle_x = I915_BIT_6_SWIZZLE_UNKNOWN;
> -				swizzle_y = I915_BIT_6_SWIZZLE_UNKNOWN;
> +				swizzle_x = I915_BIT_6_SWIZZLE_9_10;
> +				swizzle_y = I915_BIT_6_SWIZZLE_9;
>  			}
>  			break;
>  		}
>
> You'll get typical swizzling corruption if any tiled buffers get swapped
> out, but that shouldn't happen because Ubuntu 9.04 is stuck with DRI1 so
> all tiled buffers are pinned.  Note that DRI1 with compiz has many
> graphical corruption and stability issues that are fixed with DRI2, but
> I'm not sure that what you're seeing is one of those.
>
> If that patch doesn't make things work, then to fix a giant pile of
> userland bugs that might account for it, update to the 2.7.0 2D driver
> and enable UXA, which will get you DRI2.
>
> If the revert + small diff fixes things, I'm interested in seeing the
> output of either reg_dumper from a compile of the 2D driver or a printk
> of dcc in that function, combined with a screenshot of mesa's readpix
> demo, on master (no reverts or anything).
>
>   
Ok, I did some testing and found the following:

No screen freezing
   EXA
   UXA + bisected commit
   UXA + intel 2.7.99
Screen freezing
   UXA + intel 2.6/2.7
   UXA + patch

So, your patch didn't fix the problem, actually it reintroduced it.


I'm also experiencing a major memory leek whenever I enable UXA.
It doesn't seem to matter if the kernel is 2.6.28 or 2.6.30-rc,
it also doesn't matter if the intel driver is version 2.6, 2.7 or 2.7.99.
After about 3-4 hours I have to restart the xserver because of major 
swap usage.
The two proccesses that are eating memory are Xorg and Compiz.

Do you think this is a kernel or userspace issue?

Justin Madru


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/