[RFC PATCH 2/8] vb2: simplify qbuf/prepare_buf by removing callback.

Hans Verkuil
2013-11-21T15:22:42Z

From: Hans Verkuil <hans.verkuil@cisco.com>

The callback used to merge the common code of the qbuf/prepare_buf
code can be removed now that the mmap_sem handling is pushed down to
__buf_prepare(). This makes the code more readable.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
drivers/media/v4l2-core/videobuf2-core.c | 118 +++++++++++++++----------------
1 file changed, 59 insertions(+), 59 deletions(-)

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index d2b2efb..e90a5be 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -1259,14 +1259,8 @@ static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b)
}

static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
- const char *opname,
- int (*handler)(struct vb2_queue *,
- struct v4l2_buffer *,
- struct vb2_buffer *))
+ const char *opname)
{
- struct vb2_buffer *vb;
- int ret;
-
if (q->fileio) {
dprintk(1, "%s(): file io in progress\n", opname);
return -EBUSY;
@@ -1282,8 +1276,7 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
return -EINVAL;
}

- vb = q->bufs[b->index];
- if (NULL == vb) {
+ if (q->bufs[b->index] == NULL) {
/* Should never happen */
dprintk(1, "%s(): buffer is NULL\n", opname);
return -EINVAL;
@@ -1294,30 +1287,7 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
return -EINVAL;
}

- ret = __verify_planes_array(vb, b);
- if (ret)
- return ret;
-
- ret = handler(q, b, vb);
- if (!ret) {
- /* Fill buffer information for the userspace */
- __fill_v4l2_buffer(vb, b);
-
- dprintk(1, "%s() of buffer %d succeeded\n", opname, vb->v4l2_buf.index);
- }
- return ret;
-}
-
-static int __vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
- struct vb2_buffer *vb)
-{
- if (vb->state != VB2_BUF_STATE_DEQUEUED) {
- dprintk(1, "%s(): invalid buffer state %d\n", __func__,
- vb->state);
- return -EINVAL;
- }
-
- return __buf_prepare(vb, b);
+ return __verify_planes_array(q->bufs[b->index], b);
}

/**
@@ -1337,20 +1307,68 @@ static int __vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
*/
int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
{
- return vb2_queue_or_prepare_buf(q, b, "prepare_buf", __vb2_prepare_buf);
+ int ret = vb2_queue_or_prepare_buf(q, b, "prepare_buf");
+ struct vb2_buffer *vb;
+
+ if (ret)
+ return ret;
+
+ vb = q->bufs[b->index];
+ if (vb->state != VB2_BUF_STATE_DEQUEUED) {
+ dprintk(1, "%s(): invalid buffer state %d\n", __func__,
+ vb->state);
+ return -EINVAL;
+ }
+
+ ret = __buf_prepare(vb, b);
+ if (!ret) {
+ /* Fill buffer information for the userspace */
+ __fill_v4l2_buffer(vb, b);
+
+ dprintk(1, "%s() of buffer %d succeeded\n", __func__, vb->v4l2_buf.index);
+ }
+ return ret;
}
EXPORT_SYMBOL_GPL(vb2_prepare_buf);

-static int __vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b,
- struct vb2_buffer *vb)
+/**
+ * vb2_qbuf() - Queue a buffer from userspace
+ * @q: videobuf2 queue
+ * @b: buffer structure passed from userspace to vidioc_qbuf handler
+ * in driver
+ *
+ * Should be called from vidioc_qbuf ioctl handler of a driver.
+ * This function:
+ * 1) verifies the passed buffer,
+ * 2) if necessary, calls buf_prepare callback in the driver (if provided), in
+ * which driver-specific buffer initialization can be performed,
+ * 3) if streaming is on, queues the buffer in driver by the means of buf_queue
+ * callback for processing.
+ *
+ * The return values from this function are intended to be directly returned
+ * from vidioc_qbuf handler in driver.
+ */
+int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
{
- int ret;
+ int ret = vb2_queue_or_prepare_buf(q, b, "qbuf");
+ struct vb2_buffer *vb;
+
+ if (ret)
+ return ret;
+
+ vb = q->bufs[b->index];
+ if (vb->state != VB2_BUF_STATE_DEQUEUED) {
+ dprintk(1, "%s(): invalid buffer state %d\n", __func__,
+ vb->state);
+ return -EINVAL;
+ }

switch (vb->state) {
case VB2_BUF_STATE_DEQUEUED:
ret = __buf_prepare(vb, b);
if (ret)
return ret;
+ break;
case VB2_BUF_STATE_PREPARED:
break;
default:
@@ -1372,29 +1390,11 @@ static int __vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b,
if (q->streaming)
__enqueue_in_driver(vb);

- return 0;
-}
+ /* Fill buffer information for the userspace */
+ __fill_v4l2_buffer(vb, b);

-/**
- * vb2_qbuf() - Queue a buffer from userspace
- * @q: videobuf2 queue
- * @b: buffer structure passed from userspace to vidioc_qbuf handler
- * in driver
- *
- * Should be called from vidioc_qbuf ioctl handler of a driver.
- * This function:
- * 1) verifies the passed buffer,
- * 2) if necessary, calls buf_prepare callback in the driver (if provided), in
- * which driver-specific buffer initialization can be performed,
- * 3) if streaming is on, queues the buffer in driver by the means of buf_queue
- * callback for processing.
- *
- * The return values from this function are intended to be directly returned
- * from vidioc_qbuf handler in driver.
- */
-int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
-{
- return vb2_queue_or_prepare_buf(q, b, "qbuf", __vb2_qbuf);
+ dprintk(1, "%s() of buffer %d succeeded\n", __func__, vb->v4l2_buf.index);
+ return 0;
}
EXPORT_SYMBOL_GPL(vb2_qbuf);

--
1.8.4.3