Commit 5278027b authored by Kieran Bingham's avatar Kieran Bingham Committed by Laurent Pinchart
Browse files

drm: rcar-du: Extend CMM HDSE documentation 



When the CMM is enabled, the HDSE offset is further adjusted to
compensate for consumed pixels.

Explain this further, with an extra comment at the point the offset is
adjusted.

Suggested-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarKieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
parent f9292174

drivers/gpu/drm/rcar-du/rcar_du_crtc.c

+5 −0
Original line number Diff line number Diff line
@@ -300,6 +300,11 @@ static void rcar_du_crtc_set_display_timing(struct rcar_du_crtc *rcrtc) 
	     | DSMR_DIPM_DISP | DSMR_CSPM;

	rcar_du_crtc_write(rcrtc, DSMR, dsmr);



	/*

	 * When the CMM is enabled, an additional offset of 25 pixels must be

	 * subtracted from the HDS (horizontal display start) and HDE

	 * (horizontal display end) registers.

	 */

	hdse_offset = 19;

	if (rcrtc->group->cmms_mask & BIT(rcrtc->index % 2))

		hdse_offset += 25;