Bug#529288: xserver-xorg-video-radeon: font corruption with mobile X1400

[Dietz Pröpper]

You:
> [ Owen, 'the patch' below refers to 
>http://cgit.freedesktop.org/xorg/xserver/commit/?id=7c8327f0a75087a85864256a9cea80dd4b86def5 
> ]
> > > Any corrupted glyph in the cache should get replaced sooner
> > > or later with or without the patch.
> >
> > Is there a way to explicitely invalidate the cache?
>
> No. The only thing that might indirectly have a similar effect is VT
> switching to console and back to X.

I think I already tried without success, but am not really sure. Will take 
a look at the next time...

> > In my observation, once a glyph is corrupted it stays corrupted.
>
> That could mean either:
>
>       * The actual glyph pixmap gets corrupted, not the glyph cache
>         pixmap. This seems rather unlikely, as this pixmap is never
>         rendered to after the glyph is stored in it.
>       * The glyph cache algorithm never evicts the corrupted glyph from
>         the cache for some reason. I don't fully understand this
>         algorithm, you may want to discuss this possibility with Owen
>         Taylor (CC'd).

Third variant, I did not wait long enough ;-). Regardless, I can still see 
corruption with ExaNoUploadToScreen but it occurs not so often (my stomach 
says, about 1/5 of the original rate) and indeed normally "heals" quite 
quickly.

> > > Does
> > >
> > > 	Option	"ExaNoUploadToScreen"
> > >
> > > work around the problem, with or without the patch?
> >
> > Currently testing without the patch, corrupted glyphs within 30min
> > after server startup.
>
> Okay, this might be the problem fixed by the patch.

Then I'll again try with the patch and report the result.