media: vsp1: Remove unbalanced .s_stream(0) calls

The VSP1 driver uses the subdev .s_stream() operation to stop WPF
instances, without a corresponding call to start them. The V4L2 subdev
core started warning about unbalanced .s_stream() calls in commit
009905e ("media: v4l2-subdev: Document and enforce .s_stream()
requirements"), causing a regression with this driver.

Fix the problem by replacing the .s_stream() operation with an explicit
function call for WPF instances. This allows sharing an additional data
structure between RPF and WPF instances.

Fixes: 009905e ("media: v4l2-subdev: Document and enforce .s_stream() requirements")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Closes: https://lore.kernel.org/linux-media/2221395-6a9b-9527-d697-e76aebc6af@linux-m68k.org/
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>

Author: Laurent Pinchart

drivers/media/platform/renesas/vsp1/vsp1_pipe.c

@@ -373,7 +373,7 @@ int vsp1_pipeline_stop(struct vsp1_pipeline *pipe)
 			   (7 << VI6_DPR_SMPPT_TGW_SHIFT) |
 			   (VI6_DPR_NODE_UNUSED << VI6_DPR_SMPPT_PT_SHIFT));
 
-	v4l2_subdev_call(&pipe->output->entity.subdev, video, s_stream, 0);
+	vsp1_wpf_stop(pipe->output);
 
 	return ret;
 }

drivers/media/platform/renesas/vsp1/vsp1_rpf.c

@@ -43,14 +43,6 @@ static inline void vsp1_rpf_write(struct vsp1_rwpf *rpf,
 			       data);
 }
 
-/* -----------------------------------------------------------------------------
- * V4L2 Subdevice Operations
- */
-
-static const struct v4l2_subdev_ops rpf_ops = {
-	.pad    = &vsp1_rwpf_pad_ops,
-};
-
 /* -----------------------------------------------------------------------------
  * VSP1 Entity Operations
  */
@@ -411,7 +403,7 @@ struct vsp1_rwpf *vsp1_rpf_create(struct vsp1_device *vsp1, unsigned int index)
 	rpf->entity.index = index;
 
 	sprintf(name, "rpf.%u", index);
-	ret = vsp1_entity_init(vsp1, &rpf->entity, name, 2, &rpf_ops,
+	ret = vsp1_entity_init(vsp1, &rpf->entity, name, 2, &vsp1_rwpf_subdev_ops,
 			       MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER);
 	if (ret < 0)
 		return ERR_PTR(ret);

drivers/media/platform/renesas/vsp1/vsp1_rwpf.c

@@ -24,7 +24,7 @@ struct v4l2_rect *vsp1_rwpf_get_crop(struct vsp1_rwpf *rwpf,
 }
 
 /* -----------------------------------------------------------------------------
- * V4L2 Subdevice Pad Operations
+ * V4L2 Subdevice Operations
  */
 
 static int vsp1_rwpf_enum_mbus_code(struct v4l2_subdev *subdev,
@@ -243,7 +243,7 @@ static int vsp1_rwpf_set_selection(struct v4l2_subdev *subdev,
 	return ret;
 }
 
-const struct v4l2_subdev_pad_ops vsp1_rwpf_pad_ops = {
+static const struct v4l2_subdev_pad_ops vsp1_rwpf_pad_ops = {
 	.init_cfg = vsp1_entity_init_cfg,
 	.enum_mbus_code = vsp1_rwpf_enum_mbus_code,
 	.enum_frame_size = vsp1_rwpf_enum_frame_size,
@@ -253,6 +253,10 @@ const struct v4l2_subdev_pad_ops vsp1_rwpf_pad_ops = {
 	.set_selection = vsp1_rwpf_set_selection,
 };
 
+const struct v4l2_subdev_ops vsp1_rwpf_subdev_ops = {
+	.pad    = &vsp1_rwpf_pad_ops,
+};
+
 /* -----------------------------------------------------------------------------
  * Controls
  */

drivers/media/platform/renesas/vsp1/vsp1_rwpf.h

@@ -79,9 +79,11 @@ static inline struct vsp1_rwpf *entity_to_rwpf(struct vsp1_entity *entity)
 struct vsp1_rwpf *vsp1_rpf_create(struct vsp1_device *vsp1, unsigned int index);
 struct vsp1_rwpf *vsp1_wpf_create(struct vsp1_device *vsp1, unsigned int index);
 
+void vsp1_wpf_stop(struct vsp1_rwpf *wpf);
+
 int vsp1_rwpf_init_ctrls(struct vsp1_rwpf *rwpf, unsigned int ncontrols);
 
-extern const struct v4l2_subdev_pad_ops vsp1_rwpf_pad_ops;
+extern const struct v4l2_subdev_ops vsp1_rwpf_subdev_ops;
 
 struct v4l2_rect *vsp1_rwpf_get_crop(struct vsp1_rwpf *rwpf,
 				     struct v4l2_subdev_state *sd_state);

drivers/media/platform/renesas/vsp1/vsp1_wpf.c

@@ -186,45 +186,22 @@ static int wpf_init_controls(struct vsp1_rwpf *wpf)
 }
 
 /* -----------------------------------------------------------------------------
- * V4L2 Subdevice Core Operations
+ * VSP1 Entity Operations
  */
 
-static int wpf_s_stream(struct v4l2_subdev *subdev, int enable)
+void vsp1_wpf_stop(struct vsp1_rwpf *wpf)
 {
-	struct vsp1_rwpf *wpf = to_rwpf(subdev);
 	struct vsp1_device *vsp1 = wpf->entity.vsp1;
 
-	if (enable)
-		return 0;
-
 	/*
 	 * Write to registers directly when stopping the stream as there will be
 	 * no pipeline run to apply the display list.
 	 */
 	vsp1_write(vsp1, VI6_WPF_IRQ_ENB(wpf->entity.index), 0);
 	vsp1_write(vsp1, wpf->entity.index * VI6_WPF_OFFSET +
 		   VI6_WPF_SRCRPF, 0);
-
-	return 0;
 }
 
-/* -----------------------------------------------------------------------------
- * V4L2 Subdevice Operations
- */
-
-static const struct v4l2_subdev_video_ops wpf_video_ops = {
-	.s_stream = wpf_s_stream,
-};
-
-static const struct v4l2_subdev_ops wpf_ops = {
-	.video	= &wpf_video_ops,
-	.pad    = &vsp1_rwpf_pad_ops,
-};
-
-/* -----------------------------------------------------------------------------
- * VSP1 Entity Operations
- */
-
 static void vsp1_wpf_destroy(struct vsp1_entity *entity)
 {
 	struct vsp1_rwpf *wpf = entity_to_rwpf(entity);
@@ -583,7 +560,7 @@ struct vsp1_rwpf *vsp1_wpf_create(struct vsp1_device *vsp1, unsigned int index)
 	wpf->entity.index = index;
 
 	sprintf(name, "wpf.%u", index);
-	ret = vsp1_entity_init(vsp1, &wpf->entity, name, 2, &wpf_ops,
+	ret = vsp1_entity_init(vsp1, &wpf->entity, name, 2, &vsp1_rwpf_subdev_ops,
 			       MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER);
 	if (ret < 0)
 		return ERR_PTR(ret);