[media] rcar_vin: move buffer management to .stop_streaming handler

This commit moves the "buffer in use" logic from the .buf_cleanup
handler into .stop_streaming, based on advice that this is its
proper logical home.

By ensuring the list of pointers in priv->queue_buf[] is managed
as soon as possible, we avoid warnings concerning buffers in ACTIVE
state when the system cleans up after streaming stops. This fixes a
problem with modification of buffers after their content has been
cleared for passing to userspace.

After the refactoring, the buf_init and buf_cleanup functions were
found to contain only initialisation/release steps as are carried out
elsewhere if omitted; these functions and references were removed.

Signed-off-by: William Towle <william.towle@codethink.co.uk>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

diff --git a/drivers/media/platform/soc_camera/rcar_vin.c b/drivers/media/platform/soc_camera/rcar_vin.c
index 30dc707b794607e7a07da0a0ca7978b33b413176..279ab9f6ae38f950ea549d062ab7a9db587097bb 100644 (file)
--- a/drivers/media/platform/soc_camera/rcar_vin.c
+++ b/drivers/media/platform/soc_camera/rcar_vin.c
@@ -826,72 +826,36 @@ static void rcar_vin_wait_stop_streaming(struct rcar_vin_priv *priv)
        }
 }
 
-static void rcar_vin_videobuf_release(struct vb2_buffer *vb)
+static void rcar_vin_stop_streaming(struct vb2_queue *vq)
 {
-       struct soc_camera_device *icd = soc_camera_from_vb2q(vb->vb2_queue);
+       struct soc_camera_device *icd = soc_camera_from_vb2q(vq);
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        struct rcar_vin_priv *priv = ici->priv;
-       unsigned int i;
-       int buf_in_use = 0;
+       struct list_head *buf_head, *tmp;
+       int i;
 
        spin_lock_irq(&priv->lock);
+       rcar_vin_wait_stop_streaming(priv);
 
-       /* Is the buffer in use by the VIN hardware? */
        for (i = 0; i < MAX_BUFFER_NUM; i++) {
-               if (priv->queue_buf[i] == vb) {
-                       buf_in_use = 1;
-                       break;
-               }
-       }
-
-       if (buf_in_use) {
-               rcar_vin_wait_stop_streaming(priv);
-
-               /*
-                * Capturing has now stopped. The buffer we have been asked
-                * to release could be any of the current buffers in use, so
-                * release all buffers that are in use by HW
-                */
-               for (i = 0; i < MAX_BUFFER_NUM; i++) {
-                       if (priv->queue_buf[i]) {
-                               vb2_buffer_done(priv->queue_buf[i],
+               if (priv->queue_buf[i]) {
+                       vb2_buffer_done(priv->queue_buf[i],
                                        VB2_BUF_STATE_ERROR);
-                               priv->queue_buf[i] = NULL;
-                       }
+                       priv->queue_buf[i] = NULL;
                }
-       } else {
-               list_del_init(to_buf_list(vb));
        }
 
-       spin_unlock_irq(&priv->lock);
-}
-
-static int rcar_vin_videobuf_init(struct vb2_buffer *vb)
-{
-       INIT_LIST_HEAD(to_buf_list(vb));
-       return 0;
-}
-
-static void rcar_vin_stop_streaming(struct vb2_queue *vq)
-{
-       struct soc_camera_device *icd = soc_camera_from_vb2q(vq);
-       struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
-       struct rcar_vin_priv *priv = ici->priv;
-       struct list_head *buf_head, *tmp;
-
-       spin_lock_irq(&priv->lock);
-
-       rcar_vin_wait_stop_streaming(priv);
-       list_for_each_safe(buf_head, tmp, &priv->capture)
+       list_for_each_safe(buf_head, tmp, &priv->capture) {
+               vb2_buffer_done(&list_entry(buf_head,
+                                       struct rcar_vin_buffer, list)->vb,
+                               VB2_BUF_STATE_ERROR);
                list_del_init(buf_head);
-
+       }
        spin_unlock_irq(&priv->lock);
 }
 
 static struct vb2_ops rcar_vin_vb2_ops = {
        .queue_setup    = rcar_vin_videobuf_setup,
-       .buf_init       = rcar_vin_videobuf_init,
-       .buf_cleanup    = rcar_vin_videobuf_release,
        .buf_queue      = rcar_vin_videobuf_queue,
        .stop_streaming = rcar_vin_stop_streaming,
        .wait_prepare   = vb2_ops_wait_prepare,