Commit e948bcaf authored by Tomi Valkeinen's avatar Tomi Valkeinen
Browse files

drm/bridge: cdns-dsi: Adjust mode to negative syncs 



The Cadence DSI requires negative syncs from the incoming video signal,
but at the moment that requirement is not expressed in any way. If the
crtc decides to use positive syncs, things break down.

Use the adjusted_mode in atomic_check to set the sync flags to negative
ones.

Reviewed-by: default avatarAradhya Bhatia <aradhya.bhatia@linux.dev>
Tested-by: default avatarParth Pancholi <parth.pancholi@toradex.com>
Tested-by: default avatarJayesh Choudhary <j-choudhary@ti.com>
Reviewed-by: default avatarDevarsh Thakkar <devarsht@ti.com>
Link: https://lore.kernel.org/r/20250723-cdns-dsi-impro-v5-10-e61cc06074c2@ideasonboard.com


Signed-off-by: default avatarTomi Valkeinen <tomi.valkeinen@ideasonboard.com>
parent c92765d5

drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c

+5 −1
Original line number Diff line number Diff line
@@ -908,9 +908,13 @@ static int cdns_dsi_bridge_atomic_check(struct drm_bridge *bridge, 
	struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge);

	struct cdns_dsi *dsi = input_to_dsi(input);

	struct cdns_dsi_bridge_state *dsi_state = to_cdns_dsi_bridge_state(bridge_state);

	const struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;

	struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;

	struct cdns_dsi_cfg *dsi_cfg = &dsi_state->dsi_cfg;



	/* cdns-dsi requires negative syncs */

	adjusted_mode->flags &= ~(DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC);

	adjusted_mode->flags |= DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC;



	return cdns_dsi_check_conf(dsi, adjusted_mode, dsi_cfg);

}