[Mesa-dev] [PATCH] mesa: Restore NULL context check in _mesa_reference_renderbuffer_().

[Brian Paul]

On 12/08/2012 01:10 AM, Kenneth Graunke wrote:
> Starting KDE on i965 makes the X server die in a fire with the following
> assertion:
>
> X: intel_fbo.c:94: intel_delete_renderbuffer: Assertion `irb' failed.
>
> Obviously, this is rather unpleasant.  Bisecting revealed that:
>
> 006918c0db77e945ac56b15bc64eba502b86d56c is the first bad commit
> commit 006918c0db77e945ac56b15bc64eba502b86d56c
> Author: Brian Paul<brianp at vmware.com>
> Date:   Sat Dec 1 10:52:42 2012 -0700
>
>      mesa: remove warning message in _mesa_reference_renderbuffer_()
>
>      We were warning when there was no current context and we're about
>      to delete a renderbuffer, but that happens fairly often and isn't
>      really a problem.
>
>      Fixes http://bugs.freedesktop.org/show_bug.cgi?id=57754
>
>      Note: This is a candidate for the stable branches.
>
>      Tested-by: Ian Romanick<ian.d.romanick at intel.com>
>
> This commit removed not only the "else emit warning" block, but the
> whole NULL check as well.  Apparently it's necessary, so put it back.


Hi Kenneth,

The assertion says the 'irb' is null, but you're checking if the 
context is null.  Off hand, I think a irb==null check is needed in 
intel_delete_renderbuffer().  Maybe seeing a stack trace would shed 
more light on where the null irb/ctx is coming from.

In any case, if you need to check for ctx==null, please do that in 
intel_delete_renderbuffer().

The deal is that some (most?) drivers don't need a context handle in 
order to free a renderbuffer.  In the gallium state tracker we use the 
context to free a piece of context state that's associated with a 
renderbuffer, but the renderbuffer itself can be freed without a context.

Sorry for the headaches this one is causing.

-Brian