[Intel-gfx] [PATCH v2 1/3] drm/i915: Record the ringbuffer associated with the request

[Chris Wilson]

The request tells us where to read the ringbuf from, so use that
information to simplify the error capture. If no request was active at
the time of the hang, the ring is idle and there is no information
inside the ring pertaining to the hang.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_gpu_error.c | 29 ++++++++++-------------------
 1 file changed, 10 insertions(+), 19 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 3e137fc701cf..6eefe9c36931 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -995,7 +995,7 @@ static void i915_gem_record_rings(struct drm_device *dev,
 
 	for (i = 0; i < I915_NUM_RINGS; i++) {
 		struct intel_engine_cs *ring = &dev_priv->ring[i];
-		struct intel_ringbuffer *rbuf;
+		struct intel_ringbuffer *rbuf = NULL;
 
 		error->ring[i].pid = -1;
 
@@ -1039,26 +1039,17 @@ static void i915_gem_record_rings(struct drm_device *dev,
 				}
 				rcu_read_unlock();
 			}
+
+			rbuf = request->ringbuf;
 		}
 
-		if (i915.enable_execlists) {
-			/* TODO: This is only a small fix to keep basic error
-			 * capture working, but we need to add more information
-			 * for it to be useful (e.g. dump the context being
-			 * executed).
-			 */
-			if (request)
-				rbuf = request->ctx->engine[ring->id].ringbuf;
-			else
-				rbuf = ring->default_context->engine[ring->id].ringbuf;
-		} else
-			rbuf = ring->buffer;
-
-		error->ring[i].cpu_ring_head = rbuf->head;
-		error->ring[i].cpu_ring_tail = rbuf->tail;
-
-		error->ring[i].ringbuffer =
-			i915_error_ggtt_object_create(dev_priv, rbuf->obj);
+		if (rbuf) {
+			error->ring[i].cpu_ring_head = rbuf->head;
+			error->ring[i].cpu_ring_tail = rbuf->tail;
+			error->ring[i].ringbuffer =
+				i915_error_ggtt_object_create(dev_priv,
+							      rbuf->obj);
+		}
 
 		error->ring[i].hws_page =
 			i915_error_ggtt_object_create(dev_priv, ring->status_page.obj);
-- 
2.6.3