media: vb2: drop VB2_BUF_STATE_PREPARED, use bool prepared/synced instead

The PREPARED state becomes a problem with the request API: a buffer
could be PREPARED but dequeued, or PREPARED and in state IN_REQUEST.

PREPARED is really not a state as such, but more a property of the
buffer. So make new 'prepared' and 'synced' bools instead to remember
whether the buffer is prepared and/or synced or not.

V4L2_BUF_FLAG_PREPARED is only set if the buffer is both synced and
prepared and in the DEQUEUED state.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

include/media/videobuf2-core.h

@@ -204,7 +204,6 @@ enum vb2_io_modes {
  * enum vb2_buffer_state - current video buffer state.
  * @VB2_BUF_STATE_DEQUEUED:	buffer under userspace control.
  * @VB2_BUF_STATE_PREPARING:	buffer is being prepared in videobuf.
- * @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_REQUEUEING:	re-queue a buffer to the driver.
  * @VB2_BUF_STATE_ACTIVE:	buffer queued in driver and possibly used
@@ -218,7 +217,6 @@ enum vb2_io_modes {
 enum vb2_buffer_state {
 	VB2_BUF_STATE_DEQUEUED,
 	VB2_BUF_STATE_PREPARING,
-	VB2_BUF_STATE_PREPARED,
 	VB2_BUF_STATE_QUEUED,
 	VB2_BUF_STATE_REQUEUEING,
 	VB2_BUF_STATE_ACTIVE,
@@ -250,6 +248,12 @@ struct vb2_buffer {
 	/* private: internal use only
 	 *
 	 * state:		current buffer state; do not change
+	 * synced:		this buffer has been synced for DMA, i.e. the
+	 *			'prepare' memop was called. It is cleared again
+	 *			after the 'finish' memop is called.
+	 * prepared:		this buffer has been prepared, i.e. the
+	 *			buf_prepare op was called. It is cleared again
+	 *			after the 'buf_finish' op is called.
 	 * queued_entry:	entry on the queued buffers list, which holds
 	 *			all buffers queued from userspace
 	 * done_entry:		entry on the list that stores all buffers ready
@@ -257,6 +261,8 @@ struct vb2_buffer {
 	 * vb2_plane:		per-plane information; do not change
 	 */
 	enum vb2_buffer_state	state;
+	bool			synced;
+	bool			prepared;
 
 	struct vb2_plane	planes[VB2_MAX_PLANES];
 	struct list_head	queued_entry;