[Intel-gfx] [PATCH] drm/i915: Only insert the mb() before updating the fence parameter

[Chris Wilson]

On Tue, 9 Oct 2012 13:14:09 +0200, Daniel Vetter <daniel at ffwll.ch> wrote:
> One thing I wonder is whether we miss any barrier between the wc
> writes to the ringbuffer and the tail update. If that's the case I
> wonder where all the bug reports are ...

Ditto. I've often wondered how we get away without a wmb() there...
 
> Last one: Which machines blow up when you drop that mb()?

pnv, though that's the only non-LLC I've been testing with the
incomplete patch so I can't say it is limited to that machine.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre