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=-11.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_NEOMUTT autolearn=unavailable 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 AF190C43387 for ; Sat, 12 Jan 2019 16:43:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7D95E20836 for ; Sat, 12 Jan 2019 16:43:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725855AbfALQnd (ORCPT ); Sat, 12 Jan 2019 11:43:33 -0500 Received: from mail.bootlin.com ([62.4.15.54]:50179 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725842AbfALQnc (ORCPT ); Sat, 12 Jan 2019 11:43:32 -0500 Received: by mail.bootlin.com (Postfix, from userid 110) id 11A352074D; Sat, 12 Jan 2019 17:43:30 +0100 (CET) Received: from localhost (lfbn-1-10718-76.w90-89.abo.wanadoo.fr [90.89.68.76]) by mail.bootlin.com (Postfix) with ESMTPSA id CEAFE20714; Sat, 12 Jan 2019 17:43:19 +0100 (CET) Date: Sat, 12 Jan 2019 17:43:19 +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: <20190112164319.whr7gwvl4oux5svz@flea> References: <20181210161729.29720-1-jagan@amarulasolutions.com> <20181210161729.29720-8-jagan@amarulasolutions.com> <20181211164900.wfmkmbrbj3nmlb3h@flea> <20190107141158.zaimizk4rlqa6xli@flea> <20190108085829.clianbtjovu3oieq@flea> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii 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 On Wed, Jan 09, 2019 at 06:57:57PM +0530, Jagan Teki wrote: > On Tue, Jan 8, 2019 at 2:28 PM Maxime Ripard wrote: > > > > On Mon, Jan 07, 2019 at 08:48:21PM +0530, Jagan Teki wrote: > > > On Mon, Jan 7, 2019 at 7:42 PM Maxime Ripard wrote: > > > > > > > > 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 = panel->lcd_vt - panel->lcd_y - panel->lcd_vbp; > > > > > > > => (panel->lcd_vt) - panel->lcd_y - (panel->lcd_vbp) > > > > > > > => (timmings->ver_front_porch + panel->lcd_vbp + panel->lcd_y) > > > > > > > - panel->lcd_y - (panel->lcd_vbp) > > > > > > > => timmings->ver_front_porch + panel->lcd_vbp + panel->lcd_y > > > > > > > - panel->lcd_y - panel->lcd_vbp > > > > > > > => 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. > > > > > > > > > > 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. > > > > > > The panel bound with Sitronix ST7701 IC > > > http://www.startek-lcd.com/res/starteklcd/pdres/201705/20170512144242904.pdf > > > > It's the controller, not the panel > > As I said before, the datasheet of that panel doesn't have any > information except electrical characteristics and used IC which is > ST7701. > > I have one more panel, which is from Bananapi, S070WV20-CT16 ICN621 > please find the attachment for the same. > > Here is some more details of the same. > > https://github.com/yesnoandor/x300/blob/master/kernel/arch/arm/boot/dts/erobbing/x300/x300.dtsi#L81 > https://github.com/wxzed/Raspberry_5MIPI_Display/blob/master/I2C_Slave/USER/main.c#L15 > > https://github.com/eliot-shao/qcom/blob/master/icn6211_cxn0102/kernel/drivers/video/msm/mdss/mdss_i2c_interface.c#L152 > matches timings for > https://github.com/eliot-shao/qcom/blob/master/icn6211_cxn0102/kernel/arch/arm/boot/dts/qcom/dsi-mipi-2-rgb_1280p_video.dtsi#L20 > > https://github.com/zestroly/micromat/blob/master/test/raspberry/ICN6211.cpp#L169 Where did you get the timings from then? Maxime -- Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com