From patchwork Sat Apr 9 18:57:06 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kieran Bingham X-Patchwork-Id: 12808036 X-Patchwork-Delegate: kieran@bingham.xyz Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D2849C433F5 for ; Sat, 9 Apr 2022 18:57:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229775AbiDIS73 (ORCPT ); Sat, 9 Apr 2022 14:59:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53318 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229715AbiDIS73 (ORCPT ); Sat, 9 Apr 2022 14:59:29 -0400 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AA0EE10CC; Sat, 9 Apr 2022 11:57:19 -0700 (PDT) Received: from Monstersaurus.local (cpc89244-aztw30-2-0-cust3082.18-1.cable.virginm.net [86.31.172.11]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 5D741482; Sat, 9 Apr 2022 20:57:17 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1649530637; bh=RLZShEp9c6dVQcHexGi511NyGFd4MZ3TflsXFQ8hCos=; h=From:To:Cc:Subject:Date:From; b=u1OpjeuSSuZGovHkJslNpMKsSGrWSUEbcCBCEUieYhFNhb2M58XytTtdwrCKy4o5n TZg2kDuhelKsOyMHax1ufh4t1Oxb9154tokWMj2CsLtg8ziPB+1+on1GQJMIssP9Hb hsfmno1sPlHJCGmGOwDVElz7XJTOU2eO8yQwLil0= From: Kieran Bingham To: linux-renesas-soc@vger.kernel.org, dri-devel@lists.freedesktop.org Cc: Kieran Bingham , Laurent Pinchart , David Airlie , Daniel Vetter , linux-kernel@vger.kernel.org (open list) Subject: [PATCH] drm: rcar-du: Extend CMM HDSE documentation Date: Sat, 9 Apr 2022 19:57:06 +0100 Message-Id: <20220409185706.505319-1-kieran.bingham+renesas@ideasonboard.com> X-Mailer: git-send-email 2.32.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org 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 --- drivers/gpu/drm/rcar-du/rcar_du_crtc.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c index f361a604337f..23e1aedf8dc0 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;