From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_NEOMUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5090DC43387 for ; Mon, 7 Jan 2019 14:12:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2A3EA206B7 for ; Mon, 7 Jan 2019 14:12:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727555AbfAGOMK (ORCPT ); Mon, 7 Jan 2019 09:12:10 -0500 Received: from mail.bootlin.com ([62.4.15.54]:39902 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727012AbfAGOMK (ORCPT ); Mon, 7 Jan 2019 09:12:10 -0500 Received: by mail.bootlin.com (Postfix, from userid 110) id 113CE209D7; Mon, 7 Jan 2019 15:12:08 +0100 (CET) Received: from localhost (aaubervilliers-681-1-29-148.w90-88.abo.wanadoo.fr [90.88.149.148]) by mail.bootlin.com (Postfix) with ESMTPSA id D715420802; Mon, 7 Jan 2019 15:11:57 +0100 (CET) Date: Mon, 7 Jan 2019 15:11:58 +0100 From: Maxime Ripard To: Jagan Teki Cc: Chen-Yu Tsai , Michael Turquette , Stephen Boyd , linux-arm-kernel , linux-clk , linux-kernel , dri-devel , Michael Trimarchi , linux-sunxi , linux-amarula@amarulasolutions.com Subject: Re: [PATCH v5 07/17] drm/sun4i: sun6i_mipi_dsi: Refactor vertical video start delay Message-ID: <20190107141158.zaimizk4rlqa6xli@flea> References: <20181210161729.29720-1-jagan@amarulasolutions.com> <20181210161729.29720-8-jagan@amarulasolutions.com> <20181211164900.wfmkmbrbj3nmlb3h@flea> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="2f4sgk2x6n64h3fz" Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716 Sender: linux-clk-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org --2f4sgk2x6n64h3fz Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Dec 21, 2018 at 02:26:11AM +0530, Jagan Teki wrote: > On Tue, Dec 11, 2018 at 10:19 PM Maxime Ripard > wrote: > > > > On Mon, Dec 10, 2018 at 09:47:19PM +0530, Jagan Teki wrote: > > > Video start delay can be computed by subtracting total vertical > > > timing with front porch timing and with adding 1 delay line for TCON. > > > > > > BSP code form BPI-M64-bsp is computing video start delay as > > > (from linux-sunxi/ > > > drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/de_dsi.c) > > > > > > u32 vfp =3D panel->lcd_vt - panel->lcd_y - panel->lcd_vbp; > > > =3D> (panel->lcd_vt) - panel->lcd_y - (panel->lcd_vbp) > > > =3D> (timmings->ver_front_porch + panel->lcd_vbp + panel->lcd_y) > > > - panel->lcd_y - (panel->lcd_vbp) > > > =3D> timmings->ver_front_porch + panel->lcd_vbp + panel->lcd_y > > > - panel->lcd_y - panel->lcd_vbp > > > =3D> timmings->ver_front_porch > > > > > > So, update the start delay computation accordingly. > > > > > > Signed-off-by: Jagan Teki > > > > Even though it's a bit better now on my A33 board and I don't have the > > white stripes on the bottom of the display, there's still some > > flickering with your patches applied. > > > > Bisecting it seems to point at that patch, but reverting it doesn't > > make the issue go away, so it's not really clear which one exactly is > > at fault. >=20 > Is reverting this patch, work fine or not? As I was saying, it doesn't. > This patch is trying to make use of front porch instead of existing > back porch to compute the delay. Since we revert the VBP fix patch[1] > to assume VBP as VFP value look like your setup would also require to > revert this change. But as per BSP or drm_mode details all of my > displays even work with and w/o reverting these two. Again, I cannot help you without the datasheet for the panels you're trying to submit. Maxime --=20 Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com --2f4sgk2x6n64h3fz Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRcEzekXsqa64kGDp7j7w1vZxhRxQUCXDNeLgAKCRDj7w1vZxhR xZcmAQD+Vb+9GVQqhaYBdMGINgctl0C0OJbmlIIp5NIuvS7qTQEA5RSgws23ZINC hEiM5577HRtlW0Q8p0cQaAY4ZIT0hA0= =l3Hj -----END PGP SIGNATURE----- --2f4sgk2x6n64h3fz--