If wrap just happened we need to prevent emitting waits for pre wrap values. Detect this and emit no-ops instead.
v2: Use olr > seqno to detect wrap instead of *seqno == 0 as suggested by Chris Wilson. Signed-off-by: Mika Kuoppala <[email protected]> --- drivers/gpu/drm/i915/intel_ringbuffer.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 36e1e13a..2305af5 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -626,11 +626,22 @@ gen6_ring_sync(struct intel_ring_buffer *waiter, if (ret) return ret; - intel_ring_emit(waiter, - dw1 | signaller->semaphore_register[waiter->id]); - intel_ring_emit(waiter, seqno); - intel_ring_emit(waiter, 0); - intel_ring_emit(waiter, MI_NOOP); + BUG_ON(!waiter->outstanding_lazy_request); + + /* If seqno wrap happened, omit the wait with no-ops */ + if (likely(waiter->outstanding_lazy_request > seqno)) { + intel_ring_emit(waiter, + dw1 | + signaller->semaphore_register[waiter->id]); + intel_ring_emit(waiter, seqno); + intel_ring_emit(waiter, 0); + intel_ring_emit(waiter, MI_NOOP); + } else { + intel_ring_emit(waiter, MI_NOOP); + intel_ring_emit(waiter, MI_NOOP); + intel_ring_emit(waiter, MI_NOOP); + intel_ring_emit(waiter, MI_NOOP); + } intel_ring_advance(waiter); return 0; -- 1.7.9.5 _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
