[Intel-gfx] [PATCH 2/2] drm/i915: Fix semaphore emission for BDW+ RCS ringbuffer emission

[Chris Wilson]

The required number of dwords for semaphore emission on BDW RCS is 8,
not 6 - leading to ring buffer corruption and immediate GPU hangs when
using ringbuffer submission.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/intel_ringbuffer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 62756eb2bd4a..4729ac7ac122 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2117,7 +2117,7 @@ int intel_init_render_ring_buffer(struct intel_engine_cs *engine)
 
 			num_rings =
 				hweight32(INTEL_INFO(dev_priv)->ring_mask) - 1;
-			engine->emit_breadcrumb_sz += num_rings * 6;
+			engine->emit_breadcrumb_sz += num_rings * 8;
 		}
 	} else if (INTEL_GEN(dev_priv) >= 6) {
 		engine->init_context = intel_rcs_ctx_init;
-- 
2.11.0