Messages in this thread | | | Subject | Re: [PATCH] drm/i915: By default, enable RC6 on IVB and SNB when reasonable | From | David Woodhouse <> | Date | Wed, 23 Nov 2011 15:36:13 +0000 |
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On Wed, 2011-11-23 at 16:31 +0100, Daniel Vetter wrote: > > Things I've tried that don't work around the issue: > - Disable dmar for the igfx with intel_iommu=igfx_off > - Apply the ilk workaround (i.e. synchronous dmar tlb flushes + gpu > idling while flushing).
Well, the ILK workaround was only ensuring that the gfx was idle while the *graphics* IOTLB was flushed. We are still flushing the IOTLB for *other* IOMMUs at arbitrary times.
Might be interesting to go for *deferred* IOTLB flushes (i.e. the normal mode without the workaround or 'intel_iommu=strict' on the command line), *BUT* to make sure the batched flush (the flush_unmaps() call) can *only* happen when the GPU is quiescent. You could do that with a dirty hack for testing, and if *that* fixes the issue.... well, $DEITY knows, someone still needs a good kicking, but at least we'll have learned something :) -- dwmw2 [unhandled content-type:application/x-pkcs7-signature] | |