[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>

1 files changed, 39 insertions, 22 deletions

diff --git a/drivers/media/video/videobuf2-core.c b/drivers/media/video/videobuf2-core.c
index 3f5c7a38e6e8..b88b5b08792b 100644
--- 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.