[media] V4L: add a new videobuf2 buffer state VB2_BUF_STATE_PREPARED

This patch prepares for a better separation of the buffer preparation
stage.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/video/videobuf2-core.c b/drivers/media/video/videobuf2-core.c
index 3f5c7a3..b88b5b0 100644 (file)
--- a/drivers/media/video/videobuf2-core.c
+++ b/drivers/media/video/videobuf2-core.c
@@ -366,6 +366,7 @@ static int __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
                b->flags |= V4L2_BUF_FLAG_DONE;
                break;
        case VB2_BUF_STATE_DEQUEUED:
+       case VB2_BUF_STATE_PREPARED:
                /* nothing */
                break;
        }
@@ -832,6 +833,33 @@ static void __enqueue_in_driver(struct vb2_buffer *vb)
        q->ops->buf_queue(vb);
 }
 
+static int __buf_prepare(struct vb2_buffer *vb, struct v4l2_buffer *b)
+{
+       struct vb2_queue *q = vb->vb2_queue;
+       int ret;
+
+       switch (q->memory) {
+       case V4L2_MEMORY_MMAP:
+               ret = __qbuf_mmap(vb, b);
+               break;
+       case V4L2_MEMORY_USERPTR:
+               ret = __qbuf_userptr(vb, b);
+               break;
+       default:
+               WARN(1, "Invalid queue type\n");
+               ret = -EINVAL;
+       }
+
+       if (!ret)
+               ret = call_qop(q, buf_prepare, vb);
+       if (ret)
+               dprintk(1, "qbuf: buffer preparation failed: %d\n", ret);
+       else
+               vb->state = VB2_BUF_STATE_PREPARED;
+
+       return ret;
+}
+
 /**
  * vb2_qbuf() - Queue a buffer from userspace
  * @q:         videobuf2 queue
@@ -841,8 +869,8 @@ static void __enqueue_in_driver(struct vb2_buffer *vb)
  * Should be called from vidioc_qbuf ioctl handler of a driver.
  * This function:
  * 1) verifies the passed buffer,
- * 2) calls buf_prepare callback in the driver (if provided), in which
- *    driver-specific buffer initialization can be performed,
+ * 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.
  *
@@ -852,7 +880,7 @@ static void __enqueue_in_driver(struct vb2_buffer *vb)
 int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
 {
        struct vb2_buffer *vb;
-       int ret = 0;
+       int ret;
 
        if (q->fileio) {
                dprintk(1, "qbuf: file io in progress\n");
@@ -881,29 +909,18 @@ int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
                return -EINVAL;
        }
 
-       if (vb->state != VB2_BUF_STATE_DEQUEUED) {
+       switch (vb->state) {
+       case VB2_BUF_STATE_DEQUEUED:
+               ret = __buf_prepare(vb, b);
+               if (ret)
+                       return ret;
+       case VB2_BUF_STATE_PREPARED:
+               break;
+       default:
                dprintk(1, "qbuf: buffer already in use\n");
                return -EINVAL;
        }
 
-       if (q->memory == V4L2_MEMORY_MMAP)
-               ret = __qbuf_mmap(vb, b);
-       else if (q->memory == V4L2_MEMORY_USERPTR)
-               ret = __qbuf_userptr(vb, b);
-       else {
-               WARN(1, "Invalid queue type\n");
-               return -EINVAL;
-       }
-
-       if (ret)
-               return ret;
-
-       ret = call_qop(q, buf_prepare, vb);
-       if (ret) {
-               dprintk(1, "qbuf: buffer preparation failed\n");
-               return ret;
-       }
-
        /*
         * Add to the queued buffers list, a buffer will stay on it until
         * dequeued in dqbuf.

diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index ea55c08..dbd10ac 100644 (file)
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -105,6 +105,7 @@ enum vb2_fileio_flags {
 /**
  * enum vb2_buffer_state - current video buffer state
  * @VB2_BUF_STATE_DEQUEUED:    buffer under userspace control
+ * @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_ACTIVE:      buffer queued in driver and possibly used
  *                             in a hardware operation
@@ -116,6 +117,7 @@ enum vb2_fileio_flags {
  */
 enum vb2_buffer_state {
        VB2_BUF_STATE_DEQUEUED,
+       VB2_BUF_STATE_PREPARED,
        VB2_BUF_STATE_QUEUED,
        VB2_BUF_STATE_ACTIVE,
        VB2_BUF_STATE_DONE,