Re: [PATCH v2 1/8] media: staging/imx: Switch to sync registration for IPU subdevs

[Rui Miguel Silva]

Hi Steve,
On Sun 28 Apr 2019 at 20:09, Steve Longerbeam wrote:
> Because the IPU sub-devices VDIC and IC are not present in the
> device-tree, platform devices were created for them instead. This
> allowed these sub-devices to be added to the media device's async
> notifier and registered asynchronously along with the other
> sub-devices that do have a device-tree presence (CSI and devices
> external to the IPU and SoC).
>
> But that approach isn't really necessary. The IPU sub-devices don't
> actually require a backing device (sd->dev is allowed to be NULL).
> And that approach can't get around the fact that the IPU sub-devices
> are not part of a device hierarchy, which makes it awkward to retrieve
> the parent IPU of these devices.
>
> By registering them synchronously, they can be registered from the CSI
> async bound notifier, so the init function for them can be given the CSI
> subdev, who's dev->parent is the IPU. That is a somewhat cleaner way
> to retrieve the parent IPU.
>
> So convert to synchronous registration for the VDIC and IC task
> sub-devices, at the time a CSI sub-device is bound. There is no longer
> a backing device for them (sd->dev is NULL), but that's ok. Also
> set the VDIC/IC sub-device owner as the IPU, so that a reference can
> be taken on the IPU module.
>
> Signed-off-by: Steve Longerbeam <slongerbeam@xxxxxxxxx>

I am trying to bisect when my capture starts to fail to work with
this series, since they are so many changes and reorg that I got
lost on some of them. But... see below.

> ---
>  drivers/staging/media/imx/imx-ic-common.c     |  70 ++--
>  drivers/staging/media/imx/imx-ic-prp.c        |  34 +-
>  drivers/staging/media/imx/imx-ic-prpencvf.c   |  70 ++--
>  drivers/staging/media/imx/imx-ic.h            |   7 +-
>  drivers/staging/media/imx/imx-media-capture.c |   7 +-
>  drivers/staging/media/imx/imx-media-csi.c     |   2 +-
>  drivers/staging/media/imx/imx-media-dev.c     | 121 +-----
>  .../staging/media/imx/imx-media-internal-sd.c | 356 ++++++++----------
>  drivers/staging/media/imx/imx-media-of.c      |  38 +-
>  drivers/staging/media/imx/imx-media-vdic.c    |  85 ++---
>  drivers/staging/media/imx/imx-media.h         |  67 ++--
>  drivers/staging/media/imx/imx7-media-csi.c    |   3 +-
>  12 files changed, 325 insertions(+), 535 deletions(-)
>
> +	dev_dbg(priv->ipu_dev, "%s: link setup %s -> %s",

<snip>

> +		sd->name, remote->entity->name, local->entity->name);
>  
>  	mutex_lock(&priv->lock);
>  
> @@ -864,9 +856,6 @@ static int vdic_registered(struct v4l2_subdev *sd)
>  	int i, ret;
>  	u32 code;
>  
> -	/* get media device */
> -	priv->md = dev_get_drvdata(sd->v4l2_dev->dev);
> -
>  	for (i = 0; i < VDIC_NUM_PADS; i++) {
>  		priv->pad[i].flags = (i == VDIC_SRC_PAD_DIRECT) ?
>  			MEDIA_PAD_FL_SOURCE : MEDIA_PAD_FL_SINK;
> @@ -938,77 +927,55 @@ static const struct v4l2_subdev_internal_ops vdic_internal_ops = {
>  	.unregistered = vdic_unregistered,
>  };
>  
> -static int imx_vdic_probe(struct platform_device *pdev)
> +struct v4l2_subdev *imx_media_vdic_register(struct imx_media_dev *imxmd,
> +					    struct device *ipu_dev,
> +					    struct ipu_soc *ipu,
> +					    u32 grp_id)
>  {
> -	struct imx_media_ipu_internal_sd_pdata *pdata;
> +	struct v4l2_device *v4l2_dev = &imxmd->v4l2_dev;
>  	struct vdic_priv *priv;
>  	int ret;
>  
> -	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> +	priv = devm_kzalloc(ipu_dev, sizeof(*priv), GFP_KERNEL);
>  	if (!priv)
> -		return -ENOMEM;
> +		return ERR_PTR(-ENOMEM);
>  
> -	platform_set_drvdata(pdev, &priv->sd);
> -	priv->dev = &pdev->dev;
> -
> -	pdata = priv->dev->platform_data;
> -	priv->ipu_id = pdata->ipu_id;
> +	priv->ipu_dev = ipu_dev;
> +	priv->ipu = ipu;
> +	priv->md = imxmd;
>  
>  	v4l2_subdev_init(&priv->sd, &vdic_subdev_ops);
>  	v4l2_set_subdevdata(&priv->sd, priv);
>  	priv->sd.internal_ops = &vdic_internal_ops;
>  	priv->sd.entity.ops = &vdic_entity_ops;
>  	priv->sd.entity.function = MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER;
> -	priv->sd.dev = &pdev->dev;
> -	priv->sd.owner = THIS_MODULE;
> +	priv->sd.owner = ipu_dev->driver->owner;
>  	priv->sd.flags = V4L2_SUBDEV_FL_HAS_DEVNODE;
> -	/* get our group id */
> -	priv->sd.grp_id = pdata->grp_id;
> -	strscpy(priv->sd.name, pdata->sd_name, sizeof(priv->sd.name));
> +	priv->sd.grp_id = grp_id;
> +	imx_media_grp_id_to_sd_name(priv->sd.name, sizeof(priv->sd.name),
> +				    priv->sd.grp_id, ipu_get_num(ipu));
>  
>  	mutex_init(&priv->lock);
>  
> -	ret = v4l2_async_register_subdev(&priv->sd);
> +	ret = v4l2_device_register_subdev(v4l2_dev, &priv->sd);
>  	if (ret)
>  		goto free;
>  
> -	return 0;
> +	return &priv->sd;
>  free:
>  	mutex_destroy(&priv->lock);
> -	return ret;
> +	return ERR_PTR(ret);
>  }
>  
> -static int imx_vdic_remove(struct platform_device *pdev)
> +int imx_media_vdic_unregister(struct v4l2_subdev *sd)
>  {
> -	struct v4l2_subdev *sd = platform_get_drvdata(pdev);
>  	struct vdic_priv *priv = v4l2_get_subdevdata(sd);
>  
>  	v4l2_info(sd, "Removing\n");
>  
> -	v4l2_async_unregister_subdev(sd);
> +	v4l2_device_unregister_subdev(sd);
>  	mutex_destroy(&priv->lock);
>  	media_entity_cleanup(&sd->entity);
>  
>  	return 0;
>  }
> -
> -static const struct platform_device_id imx_vdic_ids[] = {
> -	{ .name = "imx-ipuv3-vdic" },
> -	{ },
> -};
> -MODULE_DEVICE_TABLE(platform, imx_vdic_ids);
> -
> -static struct platform_driver imx_vdic_driver = {
> -	.probe = imx_vdic_probe,
> -	.remove = imx_vdic_remove,
> -	.id_table = imx_vdic_ids,
> -	.driver = {
> -		.name = "imx-ipuv3-vdic",
> -	},
> -};
> -module_platform_driver(imx_vdic_driver);
> -
> -MODULE_DESCRIPTION("i.MX VDIC subdev driver");
> -MODULE_AUTHOR("Steve Longerbeam <steve_longerbeam@xxxxxxxxxx>");
> -MODULE_LICENSE("GPL");
> -MODULE_ALIAS("platform:imx-ipuv3-vdic");

This breaks compilation until patch 6/8. I think you need to make
some makefile changes also in this patch.

WARNING: modpost: missing MODULE_LICENSE() in drivers/staging/media/imx/imx-media-ic.o
see include/linux/module.h for more information
WARNING: modpost: missing MODULE_LICENSE() in drivers/staging/media/imx/imx-media-vdic.o
see include/linux/module.h for more information
ERROR: "imx_media_ic_register" [drivers/staging/media/imx/imx-media.ko] undefined!
ERROR: "imx_media_vdic_register" [drivers/staging/media/imx/imx-media.ko] undefined!
ERROR: "imx_media_vdic_unregister" [drivers/staging/media/imx/imx-media.ko] undefined!
ERROR: "imx_media_ic_unregister" [drivers/staging/media/imx/imx-media.ko] undefined!
make[2]: *** [scripts/Makefile.modpost:91: __modpost] Error 1
make[1]: *** [/dev/shm/linux-git/Makefile:1263: modules] Error 2
make: *** [Makefile:170: sub-make] Error 2

---
Cheers,
	Rui