On Tue, Jul 30, 2013 at 4:10 PM, Maarten Lankhorst maarten.lankhorst@canonical.com wrote:
Op 30-07-13 04:42, Ben Skeggs schreef:
On Tue, Jul 23, 2013 at 11:43 PM, Maarten Lankhorst maarten.lankhorst@canonical.com wrote:
Sort of fixes mmiotrace for me again, I could sear I sent a similar patch before the rework to event interface, so I guess it got reintroduced.
I don't know how/why you think this fixes anything. The interrupt handler can't possibly be called until after priv->base.vblank has been initialised...
Seriously, go look, the subdev interrupt handler pointer isn't filled in (and can't be) until after nouveau_disp_create() has been called, and nouveau_disp_create() initialises priv->base.vblank before it returns...
There's also a disp_dtor function right above it and without a smp_wmb the writes could still be reordered in the constructor. O:-) A spinlock would be needed to make sure that no interrupt is in process if you set intr to null before destroying vblank event, though.
I can probably try to get the oops again indicating that priv->base.vblank was null in the interrupt handler if you want, iirc it happened reliably during mmiotracing.
It would've had to have happened during a module unload in that case, I can't see how else it could've possibly happened.
The destructor case is valid though, but not really a critical issue, so I'd rather find a better solution than these hacked checks :) I'll add it to the list...
Ben.
~Maarten