During the reset of ring submission, we first stop the engine by clearing the HEAD/TAIL and marking the ring as disabled. However, it would be safer to disable the ring (after emptying) before resetting the HEAD/TAIL.
Suggested-by: Mika Kuoppala <mika.kuopp...@linux.intel.com> Signed-off-by: Chris Wilson <ch...@chris-wilson.co.uk> Cc: Mika Kuoppala <mika.kuopp...@linux.intel.com> --- drivers/gpu/drm/i915/gt/intel_ring_submission.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_ring_submission.c b/drivers/gpu/drm/i915/gt/intel_ring_submission.c index 44159595d909..8a5314b97b04 100644 --- a/drivers/gpu/drm/i915/gt/intel_ring_submission.c +++ b/drivers/gpu/drm/i915/gt/intel_ring_submission.c @@ -301,13 +301,17 @@ static void xcs_sanitize(struct intel_engine_cs *engine) static bool stop_ring(struct intel_engine_cs *engine) { + /* Empty the ring by skipping to the end */ ENGINE_WRITE_FW(engine, RING_HEAD, ENGINE_READ_FW(engine, RING_TAIL)); - - ENGINE_WRITE_FW(engine, RING_HEAD, 0); - ENGINE_WRITE_FW(engine, RING_TAIL, 0); + ENGINE_POSTING_READ(engine, RING_HEAD); /* The ring must be empty before it is disabled */ ENGINE_WRITE_FW(engine, RING_CTL, 0); + ENGINE_POSTING_READ(engine, RING_CTL); + + /* Then reset the disabled ring */ + ENGINE_WRITE_FW(engine, RING_HEAD, 0); + ENGINE_WRITE_FW(engine, RING_TAIL, 0); return (ENGINE_READ_FW(engine, RING_HEAD) & HEAD_ADDR) == 0; } -- 2.20.1 _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx