On Tue, Nov 29, 2011 at 03:35:54PM +0000, Chris Wilson wrote:
On Tue, 29 Nov 2011 16:09:29 +0100, Daniel Vetter daniel.vetter@ffwll.ch wrote:
Usually results in (rare) cursor corruptions on platforms requiring physically addressed cursors.
So the phys cursor pages are set to WC upon creation, are we just missing the mb()? Or more likely the CPUs don't have PAT and we are being lazy in not detecting the error.
Yes, on reconsidering the tested-by is from a pentium m, which has working pat, and we do a wbinvd in the i8xx chipset flush, so I don't know anymore how this patch actually works.
But it seems to indeed fix the issue for at least one reporter and cursor update is about as far away from a perf critical path as possible, so who cares about such minor quibbles, it works ;-) -Daniel