[PATCH v3 1/4] drm: add devm release action

[Rodrigo Vivi]

On Mon, Apr 22, 2024 at 12:27:53PM +0530, Aravind Iddamsetty wrote:
> In scenarios where drm_dev_put is directly called by driver we want to
> release devm_drm_dev_init_release action associated with struct
> drm_device.
> 
> v2: Directly expose the original function, instead of introducing a
> helper (Rodrigo)
> 
> v3: add kernel-doc (Maxime Ripard)
> 
> Cc: Maxime Ripard <mripard at kernel.org>
> Cc: Thomas Hellstr_m <thomas.hellstrom at linux.intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> 

please avoid these empty lines here.... cc, rv-b, sign-offs, links,
etc are all in the same block.

> Reviewed-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
> Signed-off-by: Aravind Iddamsetty <aravind.iddamsetty at linux.intel.com>
> ---
>  drivers/gpu/drm/drm_drv.c | 13 +++++++++++++
>  include/drm/drm_drv.h     |  2 ++
>  2 files changed, 15 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index 243cacb3575c..9d0409165f1e 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -714,6 +714,19 @@ static int devm_drm_dev_init(struct device *parent,
>  					devm_drm_dev_init_release, dev);
>  }
>  
> +/**
> + * devm_drm_dev_release_action - Call the final release action of the device

Seeing the doc here gave me a second thought....

the original release should be renamed to _devm_drm_dev_release
and this should be called devm_drm_dev_release without the 'action' word.

> + * @dev: DRM device
> + *
> + * In scenarios where drm_dev_put is directly called by driver we want to release
> + * devm_drm_dev_init_release action associated with struct drm_device.

But also, this made me more confusing on why this is needed.
Why can't we call put and get back?

The next needs to make it clear on why we need to release in these
scenarios regarless of the number of counters. But do we really
want this?

Can we block the flr if we have users? Perhaps this is the reason
that on my side the flr was not that clean? beucase I had display
so I had clients connected?

> + */
> +void devm_drm_dev_release_action(struct drm_device *dev)
> +{
> +	devm_release_action(dev->dev, devm_drm_dev_init_release, dev);
> +}
> +EXPORT_SYMBOL(devm_drm_dev_release_action);
> +
>  void *__devm_drm_dev_alloc(struct device *parent,
>  			   const struct drm_driver *driver,
>  			   size_t size, size_t offset)
> diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
> index 8878260d7529..fa9123684874 100644
> --- a/include/drm/drm_drv.h
> +++ b/include/drm/drm_drv.h
> @@ -444,6 +444,8 @@ struct drm_driver {
>  	const struct file_operations *fops;
>  };
>  
> +void devm_drm_dev_release_action(struct drm_device *dev);
> +
>  void *__devm_drm_dev_alloc(struct device *parent,
>  			   const struct drm_driver *driver,
>  			   size_t size, size_t offset);
> -- 
> 2.25.1
>