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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 5788DC742A1 for ; Thu, 11 Jul 2019 21:28:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2FC3D21019 for ; Thu, 11 Jul 2019 21:28:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728877AbfGKV2T (ORCPT ); Thu, 11 Jul 2019 17:28:19 -0400 Received: from gloria.sntech.de ([185.11.138.130]:36214 "EHLO gloria.sntech.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726446AbfGKV2T (ORCPT ); Thu, 11 Jul 2019 17:28:19 -0400 Received: from ip5f5a6320.dynamic.kabel-deutschland.de ([95.90.99.32] helo=diego.localnet) by gloria.sntech.de with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hlgbu-0006n4-SN; Thu, 11 Jul 2019 23:28:14 +0200 From: Heiko =?ISO-8859-1?Q?St=FCbner?= To: Douglas Anderson Cc: Thierry Reding , Sean Paul , linux-rockchip@lists.infradead.org, Laurent Pinchart , dri-devel@lists.freedesktop.org, Boris Brezillon , Ezequiel Garcia , Enric =?ISO-8859-1?Q?Balletb=F2?= , Rob Herring , mka@chromium.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Mark Rutland , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v5 7/7] ARM: dts: rockchip: Specify rk3288-veyron-minnie's display timings Date: Thu, 11 Jul 2019 23:28:14 +0200 Message-ID: <10427933.3dknIRnSiX@diego> In-Reply-To: <20190401171724.215780-8-dianders@chromium.org> References: <20190401171724.215780-1-dianders@chromium.org> <20190401171724.215780-8-dianders@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Montag, 1. April 2019, 19:17:24 CEST schrieb Douglas Anderson: > Just like we did for rk3288-veyron-chromebook, we want to be able to > use one of the fixed PLLs in the system to make the pixel clock for > minnie. > > Specifying these timings matches us with how the display is used on > the downstream Chrome OS kernel. See https://crrev.com/c/323211. > > Unlike what we did for rk3288-veyron-chromebook, this CL actually > changes the timings (though not the pixel clock) that is used when > using the upstream kernel. Booting up a minnie shows that it ended up > with a 66.67 MHz pixel clock but it was still using the > porches/blankings it would have wanted for a 72.5 MHz pixel clock. > > NOTE: compared to the downstream kernel, this seems to cause a > slightly different result reported in the 'modetest' command on a > Chromebook. The downstream kernel shows: > 1280x800 60 1280 1298 1330 1351 800 804 822 830 66667 > > With this patch we have: > 1280x800 59 1280 1298 1330 1351 800 804 822 830 66666 > > Specifically modetest was reporting 60 Hz on the downstream kernel but > the upstream kernel does the math and comesup with 59 (because we > actually achieve 59.45 Hz). Also upstream doesn't round the Hz up > when converting to kHz--it seems to truncate. > > ALSO NOTE: when I look at the EDID from the datasheet, I see: > -hsync -vsync > ...but it seems like we've never actually run with that so I've > continued leaving that out. > > Signed-off-by: Douglas Anderson applied for 5.4 Thanks Heiko