[PATCH 26/51] drm: Manage drm_mode_config_init with drmm_

[Noralf Trønnes]

Den 21.02.2020 22.02, skrev Daniel Vetter:
> drm_mode_config_cleanup is idempotent, so no harm in calling this
> twice. This allows us to gradually switch drivers over by removing
> explicit drm_mode_config_cleanup calls.
> 
> With this step it's not also possible that (at least for simple
> drivers) automatic resource cleanup can be done correctly without a
> drm_driver->release hook. Therefore allow this now in
> devm_drm_dev_init().
> 
> Also with drmm_ explicit drm_driver->release hooks are kinda not the
> best option, so deprecate that hook to discourage future users.
> 
> v2: Fixup the example in the kerneldoc too.
> 
> v3:
> - For paranoia, double check that minor->dev == dev in the release
>   hook, because I botched the pointer math in the drmm library.
> - Call drm_mode_config_cleanup when drmm_add_action fails, we'd be
>   missing some mutex_destroy and ida_cleanup otherwise (Laurent)
> 
> v4: Add a drmm_add_action_or_reset (like devm_ has) to encapsulate this
> pattern (Noralf).
> 
> Cc: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> Cc: "Noralf Trønnes" <noralf at tronnes.org>
> Cc: Sam Ravnborg <sam at ravnborg.org>
> Cc: Thomas Zimmermann <tzimmermann at suse.de>
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> ---

<snip>

> diff --git a/drivers/gpu/drm/drm_managed.c b/drivers/gpu/drm/drm_managed.c
> index 626656369f0b..6376be01bbc8 100644
> --- a/drivers/gpu/drm/drm_managed.c
> +++ b/drivers/gpu/drm/drm_managed.c
> @@ -134,6 +134,20 @@ int __drmm_add_action(struct drm_device *dev,
>  }
>  EXPORT_SYMBOL(__drmm_add_action);
>  
> +int __drmm_add_action_or_reset(struct drm_device *dev,
> +			       drmres_release_t action,
> +			       void *data, const char *name)
> +{
> +	int ret;
> +
> +	ret = __drmm_add_action(dev, action, data, name);
> +	if (ret)
> +		action(dev, data);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL(__drmm_add_action_or_reset);
> +
>  void drmm_remove_action(struct drm_device *dev,
>  			drmres_release_t action,
>  			void *data)
> diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c
> index 08e6eff6a179..6f7005bc597f 100644
> --- a/drivers/gpu/drm/drm_mode_config.c
> +++ b/drivers/gpu/drm/drm_mode_config.c
> @@ -25,6 +25,7 @@
>  #include <drm/drm_drv.h>
>  #include <drm/drm_encoder.h>
>  #include <drm/drm_file.h>
> +#include <drm/drm_managed.h>
>  #include <drm/drm_mode_config.h>
>  #include <drm/drm_print.h>
>  #include <linux/dma-resv.h>
> @@ -373,6 +374,11 @@ static int drm_mode_create_standard_properties(struct drm_device *dev)
>  	return 0;
>  }
>  
> +static void drm_mode_config_init_release(struct drm_device *dev, void *ptr)
> +{
> +	drm_mode_config_cleanup(dev);
> +}
> +
>  /**
>   * drm_mode_config_init - initialize DRM mode_configuration structure
>   * @dev: DRM device
> @@ -384,8 +390,10 @@ static int drm_mode_create_standard_properties(struct drm_device *dev)
>   * problem, since this should happen single threaded at init time. It is the
>   * driver's problem to ensure this guarantee.
>   *
> + * Cleanup is automatically handled through registering drm_mode_config_cleanup
> + * with drmm_add_action().
>   */
> -void drm_mode_config_init(struct drm_device *dev)
> +int drm_mode_config_init(struct drm_device *dev)
>  {
>  	mutex_init(&dev->mode_config.mutex);
>  	drm_modeset_lock_init(&dev->mode_config.connection_mutex);
> @@ -443,6 +451,9 @@ void drm_mode_config_init(struct drm_device *dev)
>  		drm_modeset_acquire_fini(&modeset_ctx);
>  		dma_resv_fini(&resv);
>  	}
> +
> +	return drmm_add_action_or_reset(dev, drm_mode_config_init_release,
> +					NULL);
>  }
>  EXPORT_SYMBOL(drm_mode_config_init);
>  
> diff --git a/include/drm/drm_managed.h b/include/drm/drm_managed.h
> index 2b1ba2ad5582..684f884b6cea 100644
> --- a/include/drm/drm_managed.h
> +++ b/include/drm/drm_managed.h
> @@ -18,6 +18,13 @@ int __must_check __drmm_add_action(struct drm_device *dev,
>  				   drmres_release_t action,
>  				   void *data, const char *name);
>  
> +#define drmm_add_action_or_reset(dev, action, data) \
> +	__drmm_add_action(dev, action, data, #action)

Copy-paste error here, you want __drmm_add_action_or_reset().

Apart from that it looks good:

Acked-by: Noralf Trønnes <noralf at tronnes.org>

> +
> +int __must_check __drmm_add_action_or_reset(struct drm_device *dev,
> +					    drmres_release_t action,
> +					    void *data, const char *name);
> +
>  void drmm_remove_action(struct drm_device *dev,
>  			drmres_release_t action,
>  			void *data);