[Nouveau] [Patch] reenable fifos if we get an error while fifos disabled

[matthieu castet]

matthieu castet wrote:
> Stephan Schmid wrote:
>> Hello,
>> while playing around with multiple fifo contexts I got fifo hangs when 
>> opening glxgears nr.3.
>> The reason is that in drm/linux_core/nouveau_fifo.c l.342 
>> engine->graph.create_context() returns -ENOMEM (I dont know why but I 
>> think this problems also appears with other errors).
> May be because of hash collision. I got similar failure, but I didn't 
> take time to investigate.
> 
> 
>> But the real problem is that then nouveau_fifo alloc() returns without 
>> reenabling fifo execution, so all fifos hang. With this patch glxgears 
>> nr.3 only prints scary messages and falls back to software rendering.
> Great.
> May be using a goto to jump at the end, could avoid code duplication.
> 
Also note that in current git, nouveau_fifo_free disable and reenable 
fifo execution.
So it should make the problem disappears.