From: Kieran Bingham Date: Sat, 9 Apr 2022 18:57:06 +0000 (+0100) Subject: drm: rcar-du: Extend CMM HDSE documentation X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=5278027b3df1a157c7f7d8e3f7e3ba2884aaeee5;p=linux.git 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: Laurent Pinchart Signed-off-by: Kieran Bingham Reviewed-by: Laurent Pinchart Signed-off-by: Laurent Pinchart --- diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c index f361a604337f6..23e1aedf8dc02 100644 --- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c +++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c @@ -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;