Re: [PATCH 0/4] media: Add devm-managed helper functions for media and V4L2 subsystems

[Laurent Pinchart]

Hi Tarang,

On Wed, Jul 23, 2025 at 03:55:04PM +0530, Tarang Raval wrote:
> This patch series introduces devm-managed versions of several commonly used
> media and V4L2 initialization functions. These helpers simplify resource
> management by leveraging the devres infrastructure, ensuring automatic
> cleanup when the associated device is detached or the driver is unloaded.

I'll let Sakari review this, but overall, I don't think we want to take
this direction. Objects need to be refcounted instead of freed at remove
time. This patch series doesn't necessarily cause a regression as such,
but it will make it more difficult to fix life time management issues in
V4L2.

> Tested with IMX219 and OV2735 camera sensors on an i.MX8MP-based platform.
> 
> Tarang Raval (4):
>   media: mc: Add devm_media_entity_pads_init() helper
>   media: v4l: async: Add devm_v4l2_async_register_subdev_sensor() helper
>   media: v4l2: subdev: Add devm_v4l2_subdev_init_finalize() helper
>   media: v4l2-ctrls: Add devm_v4l2_ctrl_handler_init() helper
> 
>  drivers/media/mc/mc-entity.c              | 19 +++++++++++++++++++
>  drivers/media/v4l2-core/v4l2-async.c      | 19 +++++++++++++++++++
>  drivers/media/v4l2-core/v4l2-ctrls-core.c | 20 ++++++++++++++++++++
>  drivers/media/v4l2-core/v4l2-subdev.c     | 18 ++++++++++++++++++
>  include/media/media-entity.h              | 20 ++++++++++++++++++++
>  include/media/v4l2-async.h                | 18 ++++++++++++++++++
>  include/media/v4l2-ctrls.h                | 19 +++++++++++++++++++
>  include/media/v4l2-subdev.h               | 17 +++++++++++++++++
>  8 files changed, 150 insertions(+)
> 

-- 
Regards,

Laurent Pinchart