[media] mtk-mdp: allocate video_device dynamically

It can fix known problems with embedded video_device structs.
Signed-off-by: Minghsiu Tsai <minghsiu.tsai@mediatek.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/platform/mtk-mdp/mtk_mdp_core.h

@@ -167,7 +167,7 @@ struct mtk_mdp_dev {
 	struct mtk_mdp_comp		*comp[MTK_MDP_COMP_ID_MAX];
 	struct v4l2_m2m_dev		*m2m_dev;
 	struct list_head		ctx_list;
-	struct video_device		vdev;
+	struct video_device		*vdev;
 	struct v4l2_device		v4l2_dev;
 	struct workqueue_struct		*job_wq;
 	struct platform_device		*vpu_dev;

drivers/media/platform/mtk-mdp/mtk_mdp_m2m.c

@@ -1236,16 +1236,22 @@ int mtk_mdp_register_m2m_device(struct mtk_mdp_dev *mdp)
 	int ret;
 
 	mdp->variant = &mtk_mdp_default_variant;
-	mdp->vdev.device_caps = V4L2_CAP_VIDEO_M2M_MPLANE | V4L2_CAP_STREAMING;
-	mdp->vdev.fops = &mtk_mdp_m2m_fops;
-	mdp->vdev.ioctl_ops = &mtk_mdp_m2m_ioctl_ops;
-	mdp->vdev.release = video_device_release_empty;
-	mdp->vdev.lock = &mdp->lock;
-	mdp->vdev.vfl_dir = VFL_DIR_M2M;
-	mdp->vdev.v4l2_dev = &mdp->v4l2_dev;
-	snprintf(mdp->vdev.name, sizeof(mdp->vdev.name), "%s:m2m",
+	mdp->vdev = video_device_alloc();
+	if (!mdp->vdev) {
+		dev_err(dev, "failed to allocate video device\n");
+		ret = -ENOMEM;
+		goto err_video_alloc;
+	}
+	mdp->vdev->device_caps = V4L2_CAP_VIDEO_M2M_MPLANE | V4L2_CAP_STREAMING;
+	mdp->vdev->fops = &mtk_mdp_m2m_fops;
+	mdp->vdev->ioctl_ops = &mtk_mdp_m2m_ioctl_ops;
+	mdp->vdev->release = video_device_release;
+	mdp->vdev->lock = &mdp->lock;
+	mdp->vdev->vfl_dir = VFL_DIR_M2M;
+	mdp->vdev->v4l2_dev = &mdp->v4l2_dev;
+	snprintf(mdp->vdev->name, sizeof(mdp->vdev->name), "%s:m2m",
 		 MTK_MDP_MODULE_NAME);
-	video_set_drvdata(&mdp->vdev, mdp);
+	video_set_drvdata(mdp->vdev, mdp);
 
 	mdp->m2m_dev = v4l2_m2m_init(&mtk_mdp_m2m_ops);
 	if (IS_ERR(mdp->m2m_dev)) {
@@ -1254,26 +1260,27 @@ int mtk_mdp_register_m2m_device(struct mtk_mdp_dev *mdp)
 		goto err_m2m_init;
 	}
 
-	ret = video_register_device(&mdp->vdev, VFL_TYPE_GRABBER, 2);
+	ret = video_register_device(mdp->vdev, VFL_TYPE_GRABBER, 2);
 	if (ret) {
 		dev_err(dev, "failed to register video device\n");
 		goto err_vdev_register;
 	}
 
 	v4l2_info(&mdp->v4l2_dev, "driver registered as /dev/video%d",
-		  mdp->vdev.num);
+		  mdp->vdev->num);
 	return 0;
 
 err_vdev_register:
 	v4l2_m2m_release(mdp->m2m_dev);
 err_m2m_init:
-	video_device_release(&mdp->vdev);
+	video_device_release(mdp->vdev);
+err_video_alloc:
 
 	return ret;
 }
 
 void mtk_mdp_unregister_m2m_device(struct mtk_mdp_dev *mdp)
 {
-	video_device_release(&mdp->vdev);
+	video_unregister_device(mdp->vdev);
 	v4l2_m2m_release(mdp->m2m_dev);
 }