dma-buf: cleanup dma_fence_describe v3

The driver and timeline name are meaningless for signaled fences.

Drop them and also print the context number.

v2: avoid the calls when the BO is already signaled.
v3: use same format as trace points for context and seqno.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Link: https://lore.kernel.org/r/20251113145332.16805-2-christian.koenig@amd.com

diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c
index 35e241041c102de771c40cace035c33475e4ea11..2bb18af369b9927ef5db52c69beae69bcf89bca2 100644 (file)
--- a/drivers/dma-buf/dma-fence.c
+++ b/drivers/dma-buf/dma-fence.c
@@ -997,19 +997,21 @@ EXPORT_SYMBOL(dma_fence_set_deadline);
  */
 void dma_fence_describe(struct dma_fence *fence, struct seq_file *seq)
 {
-       const char __rcu *timeline;
-       const char __rcu *driver;
+       const char __rcu *timeline = "";
+       const char __rcu *driver = "";
+       const char *signaled = "";
 
        rcu_read_lock();
 
-       timeline = dma_fence_timeline_name(fence);
-       driver = dma_fence_driver_name(fence);
+       if (!dma_fence_is_signaled(fence)) {
+               timeline = dma_fence_timeline_name(fence);
+               driver = dma_fence_driver_name(fence);
+               signaled = "un";
+       }
 
-       seq_printf(seq, "%s %s seq %llu %ssignalled\n",
-                  rcu_dereference(driver),
-                  rcu_dereference(timeline),
-                  fence->seqno,
-                  dma_fence_is_signaled(fence) ? "" : "un");
+       seq_printf(seq, "%llu:%llu %s %s %ssignalled\n",
+                  fence->context, fence->seqno, timeline, driver,
+                  signaled);
 
        rcu_read_unlock();
 }