From 1c26b8e09004477c070f0dccb2369438ef9e1fc9 Mon Sep 17 00:00:00 2001 From: Lyude Paul Date: Mon, 13 Jul 2020 13:07:45 -0400 Subject: drm/probe_helper: Add drm_connector_helper_funcs.mode_valid_ctx This is just an atomic version of mode_valid, which is intended to be used for situations where a driver might need to check the atomic state of objects other than the connector itself. One such example is with MST, where the maximum possible bandwidth on a connector can change dynamically irregardless of the display configuration. Changes since v1: * Use new drm logging functions * Make some corrections in the mode_valid_ctx kdoc * Return error codes or 0 from ->mode_valid_ctx() on fail, and store the drm_mode_status in an additional function parameter Changes since v2: * Don't accidentally assign ret to mode->status on success, or we'll squash legitimate mode validation results * Don't forget to assign MODE_OK to status in drm_connector_mode_valid() if we have no callbacks * Drop leftover hunk in drm_modes.h around enum drm_mode_status Changes since v3: * s/return ret/return 0/ in drm_mode_validate_pipeline() * Minor cleanup in drm_connector_mode_valid() Tested-by: Imre Deak Reviewed-by: Imre Deak Cc: Lee Shawn C Signed-off-by: Lyude Paul Link: https://patchwork.freedesktop.org/patch/msgid/20200713170746.254388-2-lyude@redhat.com --- include/drm/drm_modeset_helper_vtables.h | 42 ++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) (limited to 'include/drm') diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h index 421a30f08463..4efec30f8bad 100644 --- a/include/drm/drm_modeset_helper_vtables.h +++ b/include/drm/drm_modeset_helper_vtables.h @@ -968,6 +968,48 @@ struct drm_connector_helper_funcs { */ enum drm_mode_status (*mode_valid)(struct drm_connector *connector, struct drm_display_mode *mode); + + /** + * @mode_valid_ctx: + * + * Callback to validate a mode for a connector, irrespective of the + * specific display configuration. + * + * This callback is used by the probe helpers to filter the mode list + * (which is usually derived from the EDID data block from the sink). + * See e.g. drm_helper_probe_single_connector_modes(). + * + * This function is optional, and is the atomic version of + * &drm_connector_helper_funcs.mode_valid. + * + * To allow for accessing the atomic state of modesetting objects, the + * helper libraries always call this with ctx set to a valid context, + * and &drm_mode_config.connection_mutex will always be locked with + * the ctx parameter set to @ctx. This allows for taking additional + * locks as required. + * + * Even though additional locks may be acquired, this callback is + * still expected not to take any constraints into account which would + * be influenced by the currently set display state - such constraints + * should be handled in the driver's atomic check. For example, if a + * connector shares display bandwidth with other connectors then it + * would be ok to validate the minimum bandwidth requirement of a mode + * against the maximum possible bandwidth of the connector. But it + * wouldn't be ok to take the current bandwidth usage of other + * connectors into account, as this would change depending on the + * display state. + * + * Returns: + * 0 if &drm_connector_helper_funcs.mode_valid_ctx succeeded and wrote + * the &enum drm_mode_status value to @status, or a negative error + * code otherwise. + * + */ + int (*mode_valid_ctx)(struct drm_connector *connector, + struct drm_display_mode *mode, + struct drm_modeset_acquire_ctx *ctx, + enum drm_mode_status *status); + /** * @best_encoder: * -- cgit v1.2.3