[media] vb2: Only requeue buffers immediately once streaming is started

Buffers can be returned back to videobuf2 in driver's streamon handler. In
this case vb2_buffer_done() with buffer state VB2_BUF_STATE_QUEUED will
cause the driver's buf_queue vb2 operation to be called, queueing the same
buffer again only to be returned to videobuf2 using vb2_buffer_done() and so
on.

Add a new buffer state VB2_BUF_STATE_REQUEUEING which, when used as the
state argument to vb2_buffer_done(), will result in buffers queued to the
driver. Using VB2_BUF_STATE_QUEUED will leave the buffer to videobuf2, as it
was before "[media] vb2: allow requeuing buffers while streaming".

Fixes: ce0eff016f72 ("[media] vb2: allow requeuing buffers while streaming")
[mchehab@osg.samsung.com: fix warning: enumeration value 'VB2_BUF_STATE_REQUEUEING' not handled in switch]

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: stable@vger.kernel.org # for v4.1
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

diff --git a/drivers/media/pci/cobalt/cobalt-irq.c b/drivers/media/pci/cobalt/cobalt-irq.c
index dd4bff9cf3390a4f167c6e5d1a9ae4886dae9750..d1f5898d11ba1c046737b2bb2a7ba48fa7547b9d 100644 (file)
--- a/drivers/media/pci/cobalt/cobalt-irq.c
+++ b/drivers/media/pci/cobalt/cobalt-irq.c
@@ -139,7 +139,7 @@ done:
           also know about dropped frames. */
        cb->vb.v4l2_buf.sequence = s->sequence++;
        vb2_buffer_done(&cb->vb, (skip || s->unstable_frame) ?
-                       VB2_BUF_STATE_QUEUED : VB2_BUF_STATE_DONE);
+                       VB2_BUF_STATE_REQUEUEING : VB2_BUF_STATE_DONE);
 }
 
 irqreturn_t cobalt_irq_handler(int irq, void *dev_id)

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index 93b315459098932381d61d282cdb3f04194b18ae..0c7b6a7ad2b49c6f357be98cd710167523694caf 100644 (file)
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -715,6 +715,7 @@ static void __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
                break;
        case VB2_BUF_STATE_PREPARING:
        case VB2_BUF_STATE_DEQUEUED:
+       case VB2_BUF_STATE_REQUEUEING:
                /* nothing */
                break;
        }
@@ -1182,7 +1183,8 @@ void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
 
        if (WARN_ON(state != VB2_BUF_STATE_DONE &&
                    state != VB2_BUF_STATE_ERROR &&
-                   state != VB2_BUF_STATE_QUEUED))
+                   state != VB2_BUF_STATE_QUEUED &&
+                   state != VB2_BUF_STATE_REQUEUEING))
                state = VB2_BUF_STATE_ERROR;
 
 #ifdef CONFIG_VIDEO_ADV_DEBUG
@@ -1199,22 +1201,30 @@ void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
        for (plane = 0; plane < vb->num_planes; ++plane)
                call_void_memop(vb, finish, vb->planes[plane].mem_priv);
 
-       /* Add the buffer to the done buffers list */
        spin_lock_irqsave(&q->done_lock, flags);
-       vb->state = state;
-       if (state != VB2_BUF_STATE_QUEUED)
+       if (state == VB2_BUF_STATE_QUEUED ||
+           state == VB2_BUF_STATE_REQUEUEING) {
+               vb->state = VB2_BUF_STATE_QUEUED;
+       } else {
+               /* Add the buffer to the done buffers list */
                list_add_tail(&vb->done_entry, &q->done_list);
+               vb->state = state;
+       }
        atomic_dec(&q->owned_by_drv_count);
        spin_unlock_irqrestore(&q->done_lock, flags);
 
-       if (state == VB2_BUF_STATE_QUEUED) {
+       switch (state) {
+       case VB2_BUF_STATE_QUEUED:
+               return;
+       case VB2_BUF_STATE_REQUEUEING:
                if (q->start_streaming_called)
                        __enqueue_in_driver(vb);
                return;
+       default:
+               /* Inform any processes that may be waiting for buffers */
+               wake_up(&q->done_wq);
+               break;
        }
-
-       /* Inform any processes that may be waiting for buffers */
-       wake_up(&q->done_wq);
 }
 EXPORT_SYMBOL_GPL(vb2_buffer_done);
 

diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 22a44c2f596380856acb1bccf95f14d0c2144994..c192e1b46cdc27372dc56ba704aa630ff113dfd6 100644 (file)
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -139,6 +139,7 @@ enum vb2_io_modes {
  * @VB2_BUF_STATE_PREPARING:   buffer is being prepared in videobuf
  * @VB2_BUF_STATE_PREPARED:    buffer prepared in videobuf and by the driver
  * @VB2_BUF_STATE_QUEUED:      buffer queued in videobuf, but not in driver
+ * @VB2_BUF_STATE_REQUEUEING:  re-queue a buffer to the driver
  * @VB2_BUF_STATE_ACTIVE:      buffer queued in driver and possibly used
  *                             in a hardware operation
  * @VB2_BUF_STATE_DONE:                buffer returned from driver to videobuf, but
@@ -152,6 +153,7 @@ enum vb2_buffer_state {
        VB2_BUF_STATE_PREPARING,
        VB2_BUF_STATE_PREPARED,
        VB2_BUF_STATE_QUEUED,
+       VB2_BUF_STATE_REQUEUEING,
        VB2_BUF_STATE_ACTIVE,
        VB2_BUF_STATE_DONE,
        VB2_BUF_STATE_ERROR,