On 16/02/2023 01:10, John.C.Harrison@xxxxxxxxx wrote:
From: John Harrison <John.C.Harrison@xxxxxxxxx> Instruction from hardware arch is that stolen memory and BAR mappings are unsafe for use as ring buffers. There can be issues with cache aliasing due to the CPU access going to memory via the BAR. So, don't do it. v2: Dont use BAR mappings either. Make conditional on LLC so as not to change platforms that don't need to change (Daniele). Add 'Fixes' tags (Tvrtko). v3: Fix dumb typo. Signed-off-by: John Harrison <John.C.Harrison@xxxxxxxxx> John Harrison (2): drm/i915: Don't use stolen memory for ring buffers with LLC drm/i915: Don't use BAR mappings for ring buffers with LLC drivers/gpu/drm/i915/gt/intel_ring.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
It is doing what it laid out as the problem statement so series looks good to me.
Acked-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx> Regards, Tvrtko
