v4l2: dequeue buffers properly on VIDIOC_STREAMOFF

<UPSTREAM MERGE NOT REQUIRED>

Instead of just marking all buffers as dequeued on STREAMOFF, properly
dequeue them -- this will, most notably, make sure that any mapped
DMABUF buffers will be properly unmapped.

BUG=chromium:232121
TEST=local build, run on CrOS snow

Change-Id: Ide111378caa70cf603b3edec65b4dedd0f1e1ea0
Signed-off-by: John Sheu <sheu@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/48346
Reviewed-by: Pawel Osciak <posciak@chromium.org>

diff --git a/drivers/media/video/videobuf2-core.c b/drivers/media/video/videobuf2-core.c
index ecab4a3..0956bd2 100644 (file)
--- a/drivers/media/video/videobuf2-core.c
+++ b/drivers/media/video/videobuf2-core.c
@@ -1473,6 +1473,35 @@ int vb2_wait_for_all_buffers(struct vb2_queue *q)
 }
 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
 
+/**
+ * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
+ */
+static void __vb2_dqbuf(struct vb2_buffer *vb)
+{
+       struct vb2_queue *q = vb->vb2_queue;
+       unsigned int i;
+
+       /* nothing to do if the buffer is already dequeued */
+       if (vb->state == VB2_BUF_STATE_DEQUEUED)
+               return;
+
+       vb->state = VB2_BUF_STATE_DEQUEUED;
+
+       /* unmap DMABUF buffer
+        * TODO: this unpins the buffer(dma_buf_unmap_attachment()).. but
+        * really we want to do this just after DMA, not when the
+        * buffer is dequeued..
+        */
+       if (q->memory == V4L2_MEMORY_DMABUF) {
+               for (i = 0; i < vb->num_planes; ++i) {
+                       if (!vb->planes[i].dbuf_mapped)
+                               continue;
+                       call_memop(q, unmap_dmabuf, vb->planes[i].mem_priv);
+                       vb->planes[i].dbuf_mapped = 0;
+               }
+       }
+}
+
 /**
  * vb2_dqbuf() - Dequeue a buffer to the userspace
  * @q:         videobuf2 queue
@@ -1521,19 +1550,6 @@ int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
                return ret;
        }
 
-       /* TODO: this unpins the buffer(dma_buf_unmap_attachment()).. but
-        * really we want to do this just after DMA, not when the
-        * buffer is dequeued..
-        */
-       if (q->memory == V4L2_MEMORY_DMABUF) {
-               unsigned int i;
-
-               for (i = 0; i < vb->num_planes; ++i) {
-                       call_memop(q, unmap_dmabuf, vb->planes[i].mem_priv);
-                       vb->planes[i].dbuf_mapped = 0;
-               }
-       }
-
        switch (vb->state) {
        case VB2_BUF_STATE_DONE:
                dprintk(3, "dqbuf: Returning done buffer\n");
@@ -1550,11 +1566,12 @@ int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
        __fill_v4l2_buffer(vb, b);
        /* Remove from videobuf queue */
        list_del(&vb->queued_entry);
+       /* go back to dequeued state */
+       __vb2_dqbuf(vb);
 
        dprintk(1, "dqbuf of buffer %d, with state %d\n",
                        vb->v4l2_buf.index, vb->state);
 
-       vb->state = VB2_BUF_STATE_DEQUEUED;
        return 0;
 }
 EXPORT_SYMBOL_GPL(vb2_dqbuf);
@@ -1593,7 +1610,7 @@ static void __vb2_queue_cancel(struct vb2_queue *q)
         * Reinitialize all buffers for next use.
         */
        for (i = 0; i < q->num_buffers; ++i)
-               q->bufs[i]->state = VB2_BUF_STATE_DEQUEUED;
+               __vb2_dqbuf(q->bufs[i]);
 }
 
 /**