This works together with the retry_start_streaming mechanism to allow userspace
to start streaming even if not all required buffers have been queued.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Cc: Tomasz Stanislawski <t.stanislaws@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Kamil Debski <k.debski@samsung.com>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
        /* If buffer queue is empty, return error */
        if (list_empty(&layer->dma_queue)) {
                v4l2_err(&vpbe_dev->v4l2_dev, "buffer queue is empty\n");
-               return -EINVAL;
+               return -ENOBUFS;
        }
        /* Get the next frame from the buffer queue */
        layer->next_frm = layer->cur_frm = list_entry(layer->dma_queue.next,
 
        if (list_empty(&common->dma_queue)) {
                spin_unlock_irqrestore(&common->irqlock, flags);
                vpif_dbg(1, debug, "buffer queue is empty\n");
-               return -EIO;
+               return -ENOBUFS;
        }
 
        /* Get the next frame from the buffer queue */
 
        if (list_empty(&common->dma_queue)) {
                spin_unlock_irqrestore(&common->irqlock, flags);
                vpif_err("buffer queue is empty\n");
-               return -EIO;
+               return -ENOBUFS;
        }
 
        /* Get the next frame from the buffer queue */
 
                if (ctx->src_bufs_cnt < ctx->pb_count) {
                        mfc_err("Need minimum %d OUTPUT buffers\n",
                                        ctx->pb_count);
-                       return -EINVAL;
+                       return -ENOBUFS;
                }
        }
 
 
 
        if (count == 0) {
                mxr_dbg(mdev, "no output buffers queued\n");
-               return -EINVAL;
+               return -ENOBUFS;
        }
 
        /* block any changes in output configuration */
 
        unsigned long flags;
 
        if (count < 2)
-               return -EINVAL;
+               return -ENOBUFS;
 
        spin_lock_irqsave(&pcdev->lock, flags);
 
 
        unsigned long addr;
        int ret;
 
+       if (count == 0)
+               return -ENOBUFS;
        ret = mutex_lock_interruptible(&video->lock);
        if (ret)
                goto streamoff;