[PATCH v2 7/9] drm/ast: sil164: Transparently handle BMC support

[Jocelyn Falempe]

On 12/08/2024 11:30, Thomas Zimmermann wrote:
> Permanently set the connector status to 'connected'. Return BMC modes
> for connector if no display is attached to the physical DP connector.
> Otherwise use EDID modes as before.
> 
> If the status of the physical connector changes, the driver still
> generates a hotplug event. DRM clients will then reconfigure their
> output to a mode appropriate for either physical display or BMC.
> 
Thanks, it looks good to me.

Reviewed-by: Jocelyn Falempe <jfalempe at redhat.com>

> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
> ---
>   drivers/gpu/drm/ast/ast_sil164.c | 40 ++++++++++++++++++++++++++++++--
>   1 file changed, 38 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/ast/ast_sil164.c b/drivers/gpu/drm/ast/ast_sil164.c
> index 6e17d84f994e..940118544fae 100644
> --- a/drivers/gpu/drm/ast/ast_sil164.c
> +++ b/drivers/gpu/drm/ast/ast_sil164.c
> @@ -21,9 +21,45 @@ static const struct drm_encoder_funcs ast_sil164_encoder_funcs = {
>    * Connector
>    */
>   
> +static int ast_sil164_connector_helper_get_modes(struct drm_connector *connector)
> +{
> +	int count = drm_connector_helper_get_modes(connector);
> +
> +	if (!count) {
> +		/*
> +		 * There's no EDID data without a connected monitor. Set BMC-
> +		 * compatible modes in this case. The XGA default resolution
> +		 * should work well for all BMCs.
> +		 */
> +		count = drm_add_modes_noedid(connector, 4096, 4096);
> +		if (count)
> +			drm_set_preferred_mode(connector, 1024, 768);
> +	}
> +
> +	return count;
> +}
> +
> +static int ast_sil164_connector_helper_detect_ctx(struct drm_connector *connector,
> +						  struct drm_modeset_acquire_ctx *ctx,
> +						  bool force)
> +{
> +	enum drm_connector_status old_status, status;
> +
> +	if (connector->edid_blob_ptr)
> +		old_status = connector_status_connected;
> +	else
> +		old_status = connector_status_disconnected;
> +
> +	status = drm_connector_helper_detect_from_ddc(connector, ctx, force);
> +
> +	if (status != old_status)
> +		++connector->epoch_counter;
> +	return connector_status_connected;
> +}
> +
>   static const struct drm_connector_helper_funcs ast_sil164_connector_helper_funcs = {
> -	.get_modes = drm_connector_helper_get_modes,
> -	.detect_ctx = drm_connector_helper_detect_from_ddc,
> +	.get_modes = ast_sil164_connector_helper_get_modes,
> +	.detect_ctx = ast_sil164_connector_helper_detect_ctx,
>   };
>   
>   static const struct drm_connector_funcs ast_sil164_connector_funcs = {