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=-5.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,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 AF041C5CFFE for ; Tue, 11 Dec 2018 16:49:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7ED3920855 for ; Tue, 11 Dec 2018 16:49:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7ED3920855 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-clk-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727280AbeLKQtY (ORCPT ); Tue, 11 Dec 2018 11:49:24 -0500 Received: from mail.bootlin.com ([62.4.15.54]:60183 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726808AbeLKQtY (ORCPT ); Tue, 11 Dec 2018 11:49:24 -0500 Received: by mail.bootlin.com (Postfix, from userid 110) id DD8B3208E3; Tue, 11 Dec 2018 17:49:21 +0100 (CET) Received: from localhost (unknown [185.94.189.187]) by mail.bootlin.com (Postfix) with ESMTPSA id F06A320DC3; Tue, 11 Dec 2018 17:48:59 +0100 (CET) Date: Tue, 11 Dec 2018 17:49:00 +0100 From: Maxime Ripard To: Jagan Teki Cc: Chen-Yu Tsai , Michael Turquette , Stephen Boyd , linux-arm-kernel@lists.infradead.org, linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, 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: <20181211164900.wfmkmbrbj3nmlb3h@flea> References: <20181210161729.29720-1-jagan@amarulasolutions.com> <20181210161729.29720-8-jagan@amarulasolutions.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="o2iryg5ow5l3has3" Content-Disposition: inline In-Reply-To: <20181210161729.29720-8-jagan@amarulasolutions.com> User-Agent: NeoMutt/20180716 Sender: linux-clk-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org --o2iryg5ow5l3has3 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable 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. >=20 > 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) >=20 > 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 >=20 > So, update the start delay computation accordingly. >=20 > 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. So, just like I asked in your v4, twice, http://lists.infradead.org/pipermail/linux-arm-kernel/2018-November/615339.= html > Since the documentation is quite sparse, and a MIPI-DSI analyzer is > way too expensive, I'd really like to have at least what each of > these commits are actually fixing, and what symptoms each of these > were causing, and not just "the BSP does it". Maxime --=20 Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com --o2iryg5ow5l3has3 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRcEzekXsqa64kGDp7j7w1vZxhRxQUCXA/qfAAKCRDj7w1vZxhR xQ9uAP9KufcyAaepQ146pqXJyHiBpHHjhCG0nERCxU1HYrCa6QEA0CTXdLfEFhRU ma8TfNxYc8TtkrXtx0qDanfiHpkoRgg= =qqPn -----END PGP SIGNATURE----- --o2iryg5ow5l3has3--