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spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388686AbeKPD6y (ORCPT ); Thu, 15 Nov 2018 22:58:54 -0500 Received: from mail-it1-f195.google.com ([209.85.166.195]:50700 "EHLO mail-it1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388329AbeKPD6y (ORCPT ); Thu, 15 Nov 2018 22:58:54 -0500 Received: by mail-it1-f195.google.com with SMTP id k206-v6so30665328ite.0 for ; Thu, 15 Nov 2018 09:50:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amarulasolutions.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=lzVf+6UowpPA9Enjuej5OPcuMEiQrM4vJQfW6U0CiU4=; b=mGSg0o5aQMIhhzY0VxyLE3f/+E+Nd8rvUUuD0Qg8BI34+4chnQFNB8H3k4cpMKAsc6 zlXi0SG0Pg+YcZ/azKZT0+c007D5F9jPuEtE1nhYhCdRlm+etRY08Kii/+UCGOHhEq3/ ft6Nx5vbk9rofCTUlnVi/ATvDuqO5EnZ99+5w= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=lzVf+6UowpPA9Enjuej5OPcuMEiQrM4vJQfW6U0CiU4=; b=NGvahuLSuXEqIHK7d+PkxmwTBilGYxAu7joX+jA+YRWb9VnB62cdcxp1iGOxLwledp 4s88UA++03Ysrgy036IOrXGvl8XN4aaw4O9Jxg4bw5uSfzRdghV6vmf+TpelyPmAFldV odUedjNIU1/Uh+ShzrZyntISQ84o9wq5ONTIB3Y7FSdpacm8WTivCf5JF9X0U+f5MY/0 bNtjZwUyFbUiQy45X+n9tJIFnpaNSrqV5V/wtZL31G6vko93a6BzQWO9q01SzMczFoEQ D82Dqbpk24N5VF+jfKLfhaeXmb4gyesDhHSJ9kOeoIejNHb+LDU3E5y1e/TkRJrgUStw C6ew== X-Gm-Message-State: AGRZ1gJopuHaxSZl1gm9IqBAAIQRG2evCBr4dUZ+rHXRc+lMRyL1qSCp HeIYVYl63J1H5aFixQvjukpJEEjeDxnxC6nfM7kP3Q== X-Google-Smtp-Source: AJdET5cSlq6XyW86fAADkApH1dqU4qeMgUIsKox0mC02DlJLz2KDC9sn/zAzUB75Ls8+gQwtVGWCKUdk+pqRv6ITojE= X-Received: by 2002:a05:660c:ac1:: with SMTP id k1mr6983496itl.173.1542304205538; Thu, 15 Nov 2018 09:50:05 -0800 (PST) MIME-Version: 1.0 References: <20181113111633.20189-1-jagan@amarulasolutions.com> <20181113111633.20189-9-jagan@amarulasolutions.com> <20181115095551.uctdkfmuwlnzhjnn@flea> In-Reply-To: <20181115095551.uctdkfmuwlnzhjnn@flea> From: Jagan Teki Date: Thu, 15 Nov 2018 23:19:53 +0530 Message-ID: Subject: Re: [PATCH v4 08/26] drm/sun4i: sun6i_mipi_dsi: Fix VBP size calculation To: Maxime Ripard Cc: Chen-Yu Tsai , Icenowy Zheng , Jernej Skrabec , Vasily Khoruzhick , Rob Herring , Mark Rutland , Catalin Marinas , Will Deacon , David Airlie , dri-devel , Michael Turquette , Stephen Boyd , linux-clk , Michael Trimarchi , linux-arm-kernel , devicetree , linux-kernel , linux-sunxi@googlegroups.com, linux-amarula@amarulasolutions.com Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 15, 2018 at 3:26 PM Maxime Ripard wrote: > > Hi, > > On Tue, Nov 13, 2018 at 04:46:15PM +0530, Jagan Teki wrote: > > The horizontal and vertical back porch calculation in BSP > > code is simply following the Linux drm comment diagram, in > > include/drm/drm_modes.h which is > > > > [hv]back porch = [hv]total - [hv]sync_end > > > > BSP code form BPI-M64-bsp is calculating vertical back porch as > > (from linux-sunxi/drivers/video/sunxi/disp2/disp/de/disp_lcd.c) > > > > timmings->ver_sync_time= panel_info->lcd_vspw; > > timmings->ver_back_porch= panel_info->lcd_vbp-panel_info->lcd_vspw; > > > > vbp = panel->lcd_vbp; > > vspw = panel->lcd_vspw; > > dsi_dev[sel]->dsi_basic_size0.bits.vbp = vbp-vspw; > > dsi_dev[sel]->dsi_basic_size0.bits.vbp = panel->lcd_vbp - panel->lcd_vspw; > > => timmings->ver_back_porch + panel_info->lcd_vspw - panel_info->lcd_vspw > > => timmings->ver_back_porch > > => mode->vtotal - mode->end > > > > Which evatually same as mode->vtotal - mode->vsync_end so update the > > same in SUN6I_DSI_BASIC_SIZE0_VBP > > > > On the information note, existing SUN6I_DSI_BASIC_SIZE0_VSA is proper > > value. > > > > Signed-off-by: Jagan Teki > > I've tested your changes on my A33 board, and this commit will break > it. > > It creates vblank timeouts, and visual artifacts at the bottom of the > display. Strange, VBP is earlier gives front porch which is anyway wrong. > > Later commits seem to fix the issue, but will create some blanking on > the upper third of the display. > > 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". W/o this 2-lane panel is breaking, same vblank timeout and visual artifacts at the bottom of the panel. though the commits may reference BSP, I have at-least tested on 3 different panels for us to prove its working. > > Having some datasheet for the panels you had working would help too. Unfortunately datasheet doesn't have any required information what we actually looking for.