Bug#456780: xserver-xorg-video-ati: produces improper drop shadows with compiz

[Michel Dänzer]

On Tue, 2007-12-18 at 08:21 -0400, Zoho Vignochi wrote:
> On Tue, 2007-12-18 at 09:37 +0100, Michel Dänzer wrote:
> > On Mon, 2007-12-17 at 17:34 -0400, Zoho Vignochi wrote:
> > > Package: xserver-xorg-video-ati
> > > Version: 1:6.7.196-2
> > > Severity: normal
> > > 
> > > I use compiz as a window manager and use EXA as the acceleration method. 
> > > If I switch to XAA the effect of the drop shadow is normal however my 
> > > desktop becomes very slow, especially scrolling. 
> > > 
> > > When using EXA everything seems fine except the borders around windows 
> > > are drawn improperly.
> > 
> > This might be a Mesa driver issue. Can you try upstream Git
> > mesa_7_0_branch, in particular commit
> > 3f18c0a9f27fded8f52a5f0c5b8ad71f71c46aa2 ?
> > 
> > If you can't, or if it doesn't help, does setting the shadow radius to a
> > value that isn't a power of two (e.g. 9) work around the problem?
> 
> changing the shadow radius did not work around the problem. Also after
> looking closely, the drop shadow on the top panel as well as drop down
> menus (like the menu bar) is drawn correctly. It is just the borders
> around windows do not appear properly.

Timo Aaltonen provided some additional information on IRC:

      * It also happens on i965, but not on i91/45
      * It doesn't happen with Option "EXANoComposite" (can you confirm
        this?)

Given this, it could be due to EXA RENDER acceleration bugs in the intel
driver (for i965, maybe also i8xx) and the radeon driver (for R200,
maybe also R100). Or, maybe it's a bug in EXA itself, and the relevant
operation happens to fall back to software rendering for the unaffected
cards.

BTW, do you happen to remember if this problem already occurred with
libgl1-mesa-dri 7.0.1 and/or xserver-xorg-core 1.3?


-- 
Earthling Michel Dänzer           |          http://tungstengraphics.com
Libre software enthusiast         |          Debian, X and DRI developer