drm/i915: Record the in-flight requests at the time of a hang

Being able to tally the list of outstanding requests with the sequence
of commands in the ringbuffer is often useful evidence with respect to
driver corruption.

Note that since this is the umpteenth per-ring data structure to be added
to the error state, I've coallesced the nearby loops (the ringbuffer and
batchbuffer) into a single structure along with the list of requests.  A
later task would be to refactor the ring register state into the same
structure.

v2: Fix pretty printing of requests so that they are parsed correctly by
intel_error_decode and use the 0x%08x format for seqno for consistency

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 16 insertions, 8 deletions

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index ae73288a9699..45876e5bf2aa 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -738,7 +738,7 @@ static int i915_error_state(struct seq_file *m, void *unused)
 	drm_i915_private_t *dev_priv = dev->dev_private;
 	struct drm_i915_error_state *error;
 	unsigned long flags;
-	int i, page, offset, elt;
+	int i, j, page, offset, elt;
 
 	spin_lock_irqsave(&dev_priv->error_lock, flags);
 	if (!dev_priv->first_error) {
@@ -778,10 +778,10 @@ static int i915_error_state(struct seq_file *m, void *unused)
 				    error->pinned_bo,
 				    error->pinned_bo_count);
 
-	for (i = 0; i < ARRAY_SIZE(error->batchbuffer); i++) {
-		if (error->batchbuffer[i]) {
-			struct drm_i915_error_object *obj = error->batchbuffer[i];
+	for (i = 0; i < ARRAY_SIZE(error->ring); i++) {
+		struct drm_i915_error_object *obj;
 
+		if ((obj = error->ring[i].batchbuffer)) {
 			seq_printf(m, "%s --- gtt_offset = 0x%08x\n",
 				   dev_priv->ring[i].name,
 				   obj->gtt_offset);
@@ -793,11 +793,19 @@ static int i915_error_state(struct seq_file *m, void *unused)
 				}
 			}
 		}
-	}
 
-	for (i = 0; i < ARRAY_SIZE(error->ringbuffer); i++) {
-		if (error->ringbuffer[i]) {
-			struct drm_i915_error_object *obj = error->ringbuffer[i];
+		if (error->ring[i].num_requests) {
+			seq_printf(m, "%s --- %d requests\n",
+				   dev_priv->ring[i].name,
+				   error->ring[i].num_requests);
+			for (j = 0; j < error->ring[i].num_requests; j++) {
+				seq_printf(m, "  seqno 0x%08x, emitted %ld\n",
+					   error->ring[i].requests[j].seqno,
+					   error->ring[i].requests[j].jiffies);
+			}
+		}
+
+		if ((obj = error->ring[i].ringbuffer)) {
 			seq_printf(m, "%s --- ringbuffer = 0x%08x\n",
 				   dev_priv->ring[i].name,
 				   obj->gtt_offset);