[media] vb2: fix vb2 state check when start_streaming fails

Commit bd994ddb2a12a3ff48cd549ec82cdceaea9614df (vb2: Fix stream start and
buffer completion race) broke the buffer state check in vb2_buffer_done.

So accept all three possible states there since I can no longer tell the
difference between vb2_buffer_done called from start_streaming or from
elsewhere.

Instead add a WARN_ON at the end of start_streaming that will check whether
any buffers were added to the done list, since that implies that the wrong
state was used as well.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: stable@vger.kernel.org      # for v3.15 and up
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index d3f2a22..7f70fd5 100644 (file)
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -1165,13 +1165,10 @@ void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
        if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
                return;
 
-       if (!q->start_streaming_called) {
-               if (WARN_ON(state != VB2_BUF_STATE_QUEUED))
-                       state = VB2_BUF_STATE_QUEUED;
-       } else if (WARN_ON(state != VB2_BUF_STATE_DONE &&
-                          state != VB2_BUF_STATE_ERROR)) {
-                       state = VB2_BUF_STATE_ERROR;
-       }
+       if (WARN_ON(state != VB2_BUF_STATE_DONE &&
+                   state != VB2_BUF_STATE_ERROR &&
+                   state != VB2_BUF_STATE_QUEUED))
+               state = VB2_BUF_STATE_ERROR;
 
 #ifdef CONFIG_VIDEO_ADV_DEBUG
        /*
@@ -1783,6 +1780,12 @@ static int vb2_start_streaming(struct vb2_queue *q)
                /* Must be zero now */
                WARN_ON(atomic_read(&q->owned_by_drv_count));
        }
+       /*
+        * If done_list is not empty, then start_streaming() didn't call
+        * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or
+        * STATE_DONE.
+        */
+       WARN_ON(!list_empty(&q->done_list));
        return ret;
 }