Re: [Intel-gfx] [PATCH v2 08/15] drm/probe-helper: add drm_connector_helper_get_modes()

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Wed, Jun 08, 2022 at 10:50:38AM +0300, Jani Nikula wrote:
> Add a helper function to be used as the "default" .get_modes()
> hook. This also works as an example of what the driver .get_modes()
> hooks are supposed to do regarding the new drm_edid_read*() and
> drm_edid_connector_update() calls.
> 
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

> ---
>  drivers/gpu/drm/drm_probe_helper.c | 34 ++++++++++++++++++++++++++++++
>  include/drm/drm_probe_helper.h     |  1 +
>  2 files changed, 35 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c
> index a8d26b29bfa0..e6b8f2923aa7 100644
> --- a/drivers/gpu/drm/drm_probe_helper.c
> +++ b/drivers/gpu/drm/drm_probe_helper.c
> @@ -1049,3 +1049,37 @@ int drm_connector_helper_get_modes_from_ddc(struct drm_connector *connector)
>  	return count;
>  }
>  EXPORT_SYMBOL(drm_connector_helper_get_modes_from_ddc);
> +
> +/**
> + * drm_connector_helper_get_modes - Read EDID and update connector.
> + * @connector: The connector
> + *
> + * Read the EDID using drm_edid_read() (which requires that connector->ddc is
> + * set), and update the connector using the EDID.
> + *
> + * This can be used as the "default" connector helper .get_modes() hook if the
> + * driver does not need any special processing. This is sets the example what
> + * custom .get_modes() hooks should do regarding EDID read and connector update.
> + *
> + * Returns: Number of modes.
> + */
> +int drm_connector_helper_get_modes(struct drm_connector *connector)
> +{
> +	const struct drm_edid *drm_edid;
> +	int count;
> +
> +	drm_edid = drm_edid_read(connector);
> +
> +	/*
> +	 * Unconditionally update the connector. If the EDID was read
> +	 * succesfully, fill in the connector information derived from the
> +	 * EDID. Otherwise, if the EDID is NULL, clear the connector
> +	 * information.
> +	 */
> +	count = drm_edid_connector_update(connector, drm_edid);
> +
> +	drm_edid_free(drm_edid);
> +
> +	return count;
> +}
> +EXPORT_SYMBOL(drm_connector_helper_get_modes);
> diff --git a/include/drm/drm_probe_helper.h b/include/drm/drm_probe_helper.h
> index c80cab7a53b7..8075e02aa865 100644
> --- a/include/drm/drm_probe_helper.h
> +++ b/include/drm/drm_probe_helper.h
> @@ -27,5 +27,6 @@ void drm_kms_helper_poll_enable(struct drm_device *dev);
>  bool drm_kms_helper_is_poll_worker(void);
>  
>  int drm_connector_helper_get_modes_from_ddc(struct drm_connector *connector);
> +int drm_connector_helper_get_modes(struct drm_connector *connector);
>  
>  #endif
> -- 
> 2.30.2

-- 
Ville Syrjälä
Intel