* Maarten Lankhorst | 2014-03-07 12:36:13 [+0100]:
I can't find any kind of locking so my question is what ensures that chan is not set to NULL between nouveau_fence_done() and nouveau_fence_wait_uevent()? There are just a few opcodes in between but nothing that pauses nouveau_fence_signal().
Absolutely nothing. :-) Worse still, there's no guarantee that channel isn't freed, but hopefully that is less likely to be an issue.
Okay, so I hit the correct spot. What do we do here? Do you want the patch I posted without the WARN_ON() or do you prefer to fix this in an other way?
~Maarten
Sebastian