Re: [PATCH 04/13] drm/debugfs: Create a debugfs infrastructure for encoders

[Jani Nikula <jani.nikula@linux.intel.com>]

On Wed, 11 Jan 2023, Maíra Canal <mcanal@igalia.com> wrote:
> Introduce the ability to add DRM debugfs files to a list managed by the
> encoder and, during drm_encoder_register_all(), all added files will be
> created at once.
>
> Moreover, introduce some typesafety as struct drm_debugfs_encoder_entry
> holds a drm_encoder instead of a drm_device. So, the drivers can get
> a encoder object directly from the struct drm_debugfs_encoder_entry
> in the show() callback.
>
> Signed-off-by: Maíra Canal <mcanal@igalia.com>
> ---
>  drivers/gpu/drm/drm_debugfs.c  | 36 ++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/drm_encoder.c  |  6 ++++++
>  drivers/gpu/drm/drm_internal.h |  5 +++++
>  include/drm/drm_debugfs.h      | 26 ++++++++++++++++++++++++
>  include/drm/drm_encoder.h      | 15 ++++++++++++++
>  5 files changed, 88 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c
> index d9ec1ed5a7ec..6a763fe1b031 100644
> --- a/drivers/gpu/drm/drm_debugfs.c
> +++ b/drivers/gpu/drm/drm_debugfs.c
> @@ -36,6 +36,7 @@
>  #include <drm/drm_device.h>
>  #include <drm/drm_drv.h>
>  #include <drm/drm_edid.h>
> +#include <drm/drm_encoder.h>
>  #include <drm/drm_file.h>
>  #include <drm/drm_gem.h>
>  #include <drm/drm_managed.h>
> @@ -271,6 +272,17 @@ void drm_debugfs_connector_init(struct drm_connector *connector)
>  	drm_create_file_from_list(connector);
>  }
>  
> +void drm_debugfs_encoder_init(struct drm_encoder *encoder)
> +{
> +	struct drm_minor *minor = encoder->dev->primary;
> +	struct drm_debugfs_encoder_entry *entry, *tmp;
> +
> +	if (!minor)
> +		return;
> +
> +	drm_create_file_from_list(encoder);
> +}

Because of the macro, this just looks like entry and tmp are unused
local variables.

> diff --git a/include/drm/drm_encoder.h b/include/drm/drm_encoder.h
> index 3a09682af685..38b73f2a4e38 100644
> --- a/include/drm/drm_encoder.h
> +++ b/include/drm/drm_encoder.h
> @@ -182,6 +182,21 @@ struct drm_encoder {
>  	 */
>  	struct list_head bridge_chain;
>  
> +	/**
> +	 * @debugfs_mutex:
> +	 *
> +	 * Protects &debugfs_list access.
> +	 */
> +	struct mutex debugfs_mutex;
> +
> +	/**
> +	 * @debugfs_list:
> +	 *
> +	 * List of debugfs files to be created by the DRM encoder. The files
> +	 * must be added during drm_encoder_register_all().
> +	 */
> +	struct list_head debugfs_list;
> +

If you added an additional struct wrapper for the above debugfs stuff
(and actually defined it in a drm debugfs header where it belongs), and
added that to encoder, connector, etc., you could pass a pointer to
*that* to the drm_debugfs_add_file_to_list() and
drm_create_file_from_list() proper functions.

Less boilerplate, nicer functions, debugfs stuff grouped together and
defined in the .[ch] they're used in.

I think that would be much nicer.


BR,
Jani.



>  	const struct drm_encoder_funcs *funcs;
>  	const struct drm_encoder_helper_funcs *helper_private;
>  };

-- 
Jani Nikula, Intel Open Source Graphics Center