Bug#373949: xlibmesa-dri: [ati/r128] r128_cce_depth called without lock held

[Martijn van Oosterhout <kleptog@svana.org>]

Package: xlibmesa-dri

I have some more information to add which I think may be relevent.

After digging through various CVS repositories I came across a note
that enabling the R128_DEBUG environment variable gives more info. And
indeed, it produces lots of info, which looks similar to what follows:

r128EmitHwStateLocked: (0x3) context, setup, 
r128UpdateHwState: (0x100) context, 
r128EmitHwStateLocked: (0x1) context, 
r128UpdateHwState: (0x113) context, alpha, depth, cull, 
r128EmitHwStateLocked: (0x287) context, setup, tex0, masks, cliprects, 
r128UpdateHwState: (0x100) context, 
r128EmitHwStateLocked: (0x1) context, 

Now, I don't understand much about DRI, but it seems to me that the
Update message can only change things which have previously been
locked? There are lots of instances where "depth" is updated, but I
can't find a single instance of it ever being locked, and this is what
the message is referring to.

(I note the alpha and cull are updated but not locked either, but
there's no mention of them in the kernel module, so perhaps they are
not supported).

I think we're nearing the bug here. Hope this helps,
-- 
Martijn van Oosterhout   <kleptog@svana.org>   http://svana.org/kleptog/
> From each according to his ability. To each according to his ability to litigate.