Unverified Commit 113cc3ad authored by Jagan Teki's avatar Jagan Teki Committed by Robert Foss
Browse files

drm/bridge: Document bridge init order with pre_enable_prev_first 



In order to satisfy the MIPI DSI initialization sequence the bridge
init order has been altered with the help of pre_enable_prev_first
in pre_enable and post_disable bridge operations.

Document the affected bridge init order with an example on the
bridge operations helpers.

Signed-off-by: default avatarJagan Teki <jagan@amarulasolutions.com>
Reviewed-by: default avatarDave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: default avatarRobert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230328170752.1102347-2-jagan@amarulasolutions.com
parent e18aeeda

drivers/gpu/drm/drm_bridge.c

+14 −0
Original line number Diff line number Diff line
@@ -657,6 +657,13 @@ static void drm_atomic_bridge_call_post_disable(struct drm_bridge *bridge, 
 * bridge will be called before the previous one to reverse the @pre_enable

 * calling direction.

 *

 * Example:

 * Bridge A ---> Bridge B ---> Bridge C ---> Bridge D ---> Bridge E

 *

 * With pre_enable_prev_first flag enable in Bridge B, D, E then the resulting

 * @post_disable order would be,

 * Bridge B, Bridge A, Bridge E, Bridge D, Bridge C.

 *

 * Note: the bridge passed should be the one closest to the encoder

 */

void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge,
@@ -753,6 +760,13 @@ static void drm_atomic_bridge_call_pre_enable(struct drm_bridge *bridge, 
 * If a bridge sets @pre_enable_prev_first, then the pre_enable for the

 * prev bridge will be called before pre_enable of this bridge.

 *

 * Example:

 * Bridge A ---> Bridge B ---> Bridge C ---> Bridge D ---> Bridge E

 *

 * With pre_enable_prev_first flag enable in Bridge B, D, E then the resulting

 * @pre_enable order would be,

 * Bridge C, Bridge D, Bridge E, Bridge A, Bridge B.

 *

 * Note: the bridge passed should be the one closest to the encoder

 */

void drm_atomic_bridge_chain_pre_enable(struct drm_bridge *bridge,