Revision 53292cdb066950611e5bc2e0eb109c7edb42af78 authored by Michel Thierry on 15 April 2015, 17:11:33 UTC, committed by Jani Nikula on 23 April 2015, 20:56:52 UTC
WaIdleLiteRestore is an execlists-only workaround, and requires the driver to ensure that any context always has HEAD!=TAIL when attempting lite restore. Add two extra MI_NOOP instructions at the end of each request, but keep the requests tail pointing before the MI_NOOPs. We may not need to executed them, and this is why request->tail is sampled before adding these extra instructions. If we submit a context to the ELSP which has previously been submitted, move the tail pointer past the MI_NOOPs. This ensures HEAD!=TAIL. v2: Move overallocation to gen8_emit_request, and added note about sampling request->tail in commit message (Chris). v3: Remove redundant request->tail assignment in __i915_add_request, in lrc mode this is already set in execlists_context_queue. Do not add wa implementation details inside gem (Chris). v4: Apply the wa whenever the req has been resubmitted and update comment (Chris). Cc: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Thomas Daniel <thomas.daniel@intel.com> Signed-off-by: Michel Thierry <michel.thierry@intel.com> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
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