On Sun, 3 Apr 2011, Pawel Osciak wrote: > Drivers are now required to implement the stop_streaming() callback > to ensure that all ongoing hardware operations are finished and their > ownership of buffers is ceded. > Drivers do not have to call vb2_buffer_done() for each buffer they own > anymore. > Also remove the return value from the callback. > > Signed-off-by: Pawel Osciak <pa...@osciak.com> > --- > drivers/media/video/videobuf2-core.c | 16 ++++++++++++++-- > include/media/videobuf2-core.h | 16 +++++++--------- > 2 files changed, 21 insertions(+), 11 deletions(-) > > diff --git a/drivers/media/video/videobuf2-core.c > b/drivers/media/video/videobuf2-core.c > index 6e69584..59d5e8b 100644 > --- a/drivers/media/video/videobuf2-core.c > +++ b/drivers/media/video/videobuf2-core.c > @@ -640,6 +640,9 @@ void vb2_buffer_done(struct vb2_buffer *vb, enum > vb2_buffer_state state) > struct vb2_queue *q = vb->vb2_queue; > unsigned long flags; > > + if (atomic_read(&q->queued_count) == 0) > + return; > + > if (vb->state != VB2_BUF_STATE_ACTIVE) > return; > > @@ -1178,12 +1181,20 @@ static void __vb2_queue_cancel(struct vb2_queue *q) > unsigned int i; > > /* > - * Tell driver to stop all transactions and release all queued > + * Tell the driver to stop all transactions and release all queued > * buffers. > */ > if (q->streaming) > call_qop(q, stop_streaming, q); > + > + /* > + * All buffers should now not be in use by the driver anymore, but we > + * have to manually set queued_count to 0, as the driver was not > + * required to call vb2_buffer_done() from stop_streaming() for all > + * buffers it had queued. > + */ > q->streaming = 0; > + atomic_set(&q->queued_count, 0); > > /* > * Remove all buffers from videobuf's list... > @@ -1197,7 +1208,7 @@ static void __vb2_queue_cancel(struct vb2_queue *q) > wake_up_all(&q->done_wq); > > /* > - * Reinitialize all buffers for next use. > + * Reinitialize all buffers for future use. > */ > for (i = 0; i < q->num_buffers; ++i) > q->bufs[i]->state = VB2_BUF_STATE_DEQUEUED; > @@ -1440,6 +1451,7 @@ int vb2_queue_init(struct vb2_queue *q) > > BUG_ON(!q->ops->queue_setup); > BUG_ON(!q->ops->buf_queue); > + BUG_ON(!q->ops->stop_streaming); > > INIT_LIST_HEAD(&q->queued_list); > INIT_LIST_HEAD(&q->done_list); > diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h > index f3bdbb2..8115fe9 100644 > --- a/include/media/videobuf2-core.h > +++ b/include/media/videobuf2-core.h > @@ -184,7 +184,7 @@ struct vb2_buffer { > > /** > * struct vb2_ops - driver-specific callbacks to be implemented by the driver > - * Required: queue_setup, buf_queue. The rest is optional. > + * Required: queue_setup, buf_queue, stop_streaming. The rest is optional. > * > * @queue_setup: used to negotiate queue parameters between the userspace > * and the driver; called before memory allocation; > @@ -231,13 +231,11 @@ struct vb2_buffer { > * the driver before streaming begins (such as enabling > * the device); > * @stop_streaming: called when the 'streaming' state must be disabled; > - * drivers should stop any DMA transactions here (or wait > - * until they are finished) and give back all the buffers > - * received via buf_queue() by calling vb2_buffer_done() > - * for each of them; > - * drivers can use the vb2_wait_for_all_buffers() function > - * here to wait for asynchronous completion events that > - * call vb2_buffer_done(), such as ISRs; > + * drivers should stop any DMA transactions here (or wait > + * until they are finished) before returning; > + * drivers can use the vb2_wait_for_all_buffers() function > + * here to wait for asynchronous completion events, such > + * as ISRs; > * @buf_queue: passes a buffer to the driver; the driver may > start > * a hardware operation on that buffer; this callback > * MUST return immediately, i.e. it may NOT wait for > @@ -259,7 +257,7 @@ struct vb2_ops { > void (*buf_cleanup)(struct vb2_buffer *vb); > > int (*start_streaming)(struct vb2_queue *q); > - int (*stop_streaming)(struct vb2_queue *q); > + void (*stop_streaming)(struct vb2_queue *q);
Won't compilation break after this patch with "assignment from incompatible pointer type?" I know, it's only until it is fixed by the follow-up patches, but normally we're trying to avoid such bisection breakages. Thanks Guennadi > > void (*buf_queue)(struct vb2_buffer *vb); > }; > -- > 1.7.4.2 > --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/ -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html