On 09/11/2015 01:50 PM, Sakari Ailus wrote:
> The cache synchronisation may be a time consuming operation and thus not
> best performed in an interrupt which is a typical context for
> vb2_buffer_done() calls. This may consume up to tens of ms on some
> machines, depending on the buffer size.
>
> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> ---
> drivers/media/v4l2-core/videobuf2-core.c | 20 ++++++++++----------
> 1 file changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
> index 64fce4d..c5c0707a 100644
> --- a/drivers/media/v4l2-core/videobuf2-core.c
> +++ b/drivers/media/v4l2-core/videobuf2-core.c
> @@ -1177,7 +1177,6 @@ void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
> {
> struct vb2_queue *q = vb->vb2_queue;
> unsigned long flags;
> - unsigned int plane;
>
> if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE))
> return;
> @@ -1197,10 +1196,6 @@ void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
> dprintk(4, "done processing on buffer %d, state: %d\n",
> vb->v4l2_buf.index, state);
>
> - /* sync buffers */
> - for (plane = 0; plane < vb->num_planes; ++plane)
> - call_void_memop(vb, finish, vb->planes[plane].mem_priv);
> -
Ah, OK, so it is removed here,
> /* Add the buffer to the done buffers list */
> spin_lock_irqsave(&q->done_lock, flags);
> vb->state = state;
> @@ -2086,7 +2081,7 @@ EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
> static void __vb2_dqbuf(struct vb2_buffer *vb)
> {
> struct vb2_queue *q = vb->vb2_queue;
> - unsigned int i;
> + unsigned int plane;
>
> /* nothing to do if the buffer is already dequeued */
> if (vb->state == VB2_BUF_STATE_DEQUEUED)
> @@ -2094,13 +2089,18 @@ static void __vb2_dqbuf(struct vb2_buffer *vb)
>
> vb->state = VB2_BUF_STATE_DEQUEUED;
>
> + /* sync buffers */
> + for (plane = 0; plane < vb->num_planes; plane++)
> + call_void_memop(vb, finish, vb->planes[plane].mem_priv);
> +
to here.
I'm not sure if this is correct... So __vb2_dqbuf is called from __vb2_queue_cancel(),
but now the buf_finish() callback is called *before* the memop finish() callback,
where this was the other way around in __vb2_queue_cancel(). I don't think that is
right since buf_finish() expects that the buffer is synced for the cpu.
Was this tested with CONFIG_VIDEO_ADV_DEBUG set and with 'v4l2-compliance -s'?
Not that that would help if things are done in the wrong order...
Regards,
Hans
> /* unmap DMABUF buffer */
> if (q->memory == V4L2_MEMORY_DMABUF)
> - for (i = 0; i < vb->num_planes; ++i) {
> - if (!vb->planes[i].dbuf_mapped)
> + for (plane = 0; plane < vb->num_planes; ++plane) {
> + if (!vb->planes[plane].dbuf_mapped)
> continue;
> - call_void_memop(vb, unmap_dmabuf, vb->planes[i].mem_priv);
> - vb->planes[i].dbuf_mapped = 0;
> + call_void_memop(vb, unmap_dmabuf,
> + vb->planes[plane].mem_priv);
> + vb->planes[plane].dbuf_mapped = 0;
> }
> }
>
>
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