The ring will emit too many if semaphores are disabled since we do not add the correct number to num_dwords anymore. This was introduced: commit 52ed23253b68e1cf154b03d91bed619504cf955b Author: Ben Widawsky <benjamin.widawsky@xxxxxxxxx> Date: Mon Dec 16 20:50:38 2013 -0800 drm/i915: Don't emit mbox updates without semaphores FWIW, the bug was fixed later in the series. /me hangs head in shame. Daniel: Also note that we should have merged the read-only semaphore modparam before this patch. Reported-by: Kenneth Graunke <kenneth@xxxxxxxxxxxxx> Signed-off-by: Ben Widawsky <ben@xxxxxxxxxxxx> --- drivers/gpu/drm/i915/intel_ringbuffer.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index b106984..b242dbb 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -673,10 +673,12 @@ gen6_add_request(struct intel_ring_buffer *ring) if (ret) return ret; - for_each_ring(useless, dev_priv, i) { - u32 mbox_reg = ring->signal_mbox[i]; - if (mbox_reg != GEN6_NOSYNC) - update_mboxes(ring, mbox_reg); + if (i915_semaphore_is_enabled(dev)) { + for_each_ring(useless, dev_priv, i) { + u32 mbox_reg = ring->signal_mbox[i]; + if (mbox_reg != GEN6_NOSYNC) + update_mboxes(ring, mbox_reg); + } } intel_ring_emit(ring, MI_STORE_DWORD_INDEX); -- 1.8.5.1 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx