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=-8.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,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 1F1B8C10F0B for ; Tue, 2 Apr 2019 14:47:58 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DC87C20693 for ; Tue, 2 Apr 2019 14:47:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="MhP414VA" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DC87C20693 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-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender:Content-Type:Cc: List-Subscribe:List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: In-Reply-To:MIME-Version:References:Message-ID:Subject:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=T9fV7R3Jo0Mm9pJAmEX5dEjOYoHR9+8/dp2Tdiqs4ho=; b=MhP414VAwmgBYARwtvhHktSWE H0246BQS9Nb9oErnoc45j1fSahD7+WFX1my4n4aMZNSCy7oMwAOIsLOYQFWHbWAPR/ju5IEJ6wkD+ gfy7uEBu8ih6sbhImfWa8MgvJfwobdbWxnAT+iDS3dhjkLz0GoygJ7zXvNxYZ1CKow+aQSlM8gLI0 fgb0T/OquwPCUK0RnjDQ2mJis0/qgRIYBlVlnpxDQoHkd3tETJ71uPVarhCwIuvjHvGIeT/yUhhic n2SxfG/oTkWc2NXyrNBC2/zK4Aon6XYqmVl1MHPKKB4cE9QyVQSIdoiF2uyy0v/kLw7/0lM6ogDYQ KcfG5m49w==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hBKhb-0002CK-Sn; Tue, 02 Apr 2019 14:47:51 +0000 Received: from relay7-d.mail.gandi.net ([217.70.183.200]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hBKhX-0002BY-S6 for linux-arm-kernel@lists.infradead.org; Tue, 02 Apr 2019 14:47:49 +0000 X-Originating-IP: 90.88.30.125 Received: from localhost (aaubervilliers-681-1-89-125.w90-88.abo.wanadoo.fr [90.88.30.125]) (Authenticated sender: maxime.ripard@bootlin.com) by relay7-d.mail.gandi.net (Postfix) with ESMTPSA id 408A22000E; Tue, 2 Apr 2019 14:47:43 +0000 (UTC) Date: Tue, 2 Apr 2019 16:47:42 +0200 From: Maxime Ripard To: Jagan Teki Subject: Re: [PATCH v9 2/5] drm/sun4i: sun6i_mipi_dsi: Fix TCON DRQ set bits Message-ID: <20190402144742.gdc57oxiqv3uz4o6@flea> References: <20190303173527.31055-1-jagan@amarulasolutions.com> <20190303173527.31055-3-jagan@amarulasolutions.com> <20190304154320.uledvwz5jhzt22o3@flea> <20190307153935.uxh2hsmahw5l7h4q@flea> <20190311140923.vvtubx7wndos2rfr@flea> <20190319105648.54i6pd4l74uvp4px@flea> MIME-Version: 1.0 In-Reply-To: User-Agent: NeoMutt/20180716 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190402_074748_204468_E1ADFE04 X-CRM114-Status: GOOD ( 25.08 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: David Airlie , linux-sunxi , linux-kernel , dri-devel , Chen-Yu Tsai , Daniel Vetter , Michael Trimarchi , linux-amarula@amarulasolutions.com, linux-arm-kernel Content-Type: multipart/mixed; boundary="===============3953736402460800640==" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org --===============3953736402460800640== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="kz6w2pkvgsyb3k3x" Content-Disposition: inline --kz6w2pkvgsyb3k3x Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Thu, Mar 28, 2019 at 05:23:39PM +0530, Jagan Teki wrote: > On Tue, Mar 19, 2019 at 4:26 PM Maxime Ripard wrote: > > > > On Mon, Mar 11, 2019 at 08:28:22PM +0530, Jagan Teki wrote: > > > On Mon, Mar 11, 2019 at 7:39 PM Maxime Ripard wrote: > > > > > > > > On Thu, Mar 07, 2019 at 09:24:02PM +0530, Jagan Teki wrote: > > > > > On Thu, Mar 7, 2019 at 9:09 PM Maxime Ripard wrote: > > > > > > > > > > > > On Thu, Mar 07, 2019 at 05:49:07PM +0530, Jagan Teki wrote: > > > > > > > On Mon, Mar 4, 2019 at 9:13 PM Maxime Ripard wrote: > > > > > > > > > > > > > > > > On Sun, Mar 03, 2019 at 11:05:24PM +0530, Jagan Teki wrote: > > > > > > > > > TCON DRQ for non-burst DSI mode can computed based on horizontal > > > > > > > > > front porch value, but the current driver trying to include sync > > > > > > > > > timings along with front porch resulting wrong drq. > > > > > > > > > > > > > > > > > > This patch is trying to update the drq by subtracting hsync_start > > > > > > > > > with hdisplay, which is horizontal front porch. > > > > > > > > > > > > > > > > > > Current code: > > > > > > > > > ------------ > > > > > > > > > mode->hsync_end - mode->hdisplay => horizontal front porch + sync > > > > > > > > > > > > > > > > > > With this patch: > > > > > > > > > ---------------- > > > > > > > > > mode->hsync_start - mode->hdisplay => horizontal front porch > > > > > > > > > > > > > > > > > > BSP code form BPI-M64-bsp is computing TCON DRQ set bits > > > > > > > > > for non-burts as (from linux-sunxi/ > > > > > > > > > drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/de_dsi.c) > > > > > > > > > > > > > > > > > > => panel->lcd_ht - panel->lcd_x - panel->lcd_hbp > > > > > > > > > => (timmings->hor_front_porch + panel->lcd_hbp + panel->lcd_x) > > > > > > > > ^ + sync length + > > > > > > > > > - panel->lcd_x - panel->hbp > > > > > > > > > => timmings->hor_front_porch > > > > > > > > ^ + sync > > > > > > > > > => mode->hsync_start - mode->hdisplay > > > > > > > > > > > > > > > > s/hsync_start/hsync_end/ > > > > > > > > > > > > > > No, it should be front porch so it is hsync_start. This change is > > > > > > > trying to update DRQ set to use front porch and above evaluation from > > > > > > > BSP, result the same front front porch > > > > > > > > > > > > > > Current driver has hsync_end - hdisplay which is not front porch > > > > > > > timing (it is adding extra sync timing). > > > > > > > > > > > > It would be if you considered that the back porch actually was the > > > > > > back porch plus the sync length. I have found no such evidence, quite > > > > > > the opposite actually, everything seems to point at the fact that > > > > > > unlike the TCON, the DSI block uses the back porch as only the back > > > > > > porch. > > > > > > > > > > Sorry, I'm not clear about back porch here. > > > > > > > > > > The current code has mode->hsync_end - mode->hdisplay which is Front > > > > > porch + sync time do you think it's not? > > > > > > > > It is. > > > > > > > > > DRQ set time is pure front porch value (according BSP) as I didn't > > > > > see any information about DRQ set bits in manual or anywhere. > > > > > > > > This is what I'm telling you. If you consider the back porch as only > > > > the back porch, then the result of that BSP calculation you mentionned > > > > earlier is the front porch and the sync length. > > > > > > > > You imply that the back porch should actually be treated as the back > > > > porch and the sync length in your calculation. What makes you say so? > > > > > > I'm consider the computations accordingly to drm_modes.h and which > > > matches similar like BSP code. > > > > > > mode->hsync_end - mode->hdisplay = front porch + sync > > > > > > but the actual computation is > > > mode->hsync_start - mode->hdisplay => front porch > > > > > > Which is similar to what BSP is using. > > > > > > => panel->lcd_ht - panel->lcd_x - panel->lcd_hbp > > > => (timmings->hor_front_porch + panel->lcd_hbp + panel->lcd_x) > > > - panel->lcd_x - panel->hbp > > > => timmings->hor_front_porch > > > => mode->hsync_start - mode->hdisplay > > > > You're missing the point. What I'm asking for is why you think that > > panel->lcd_ht == (timmings->hor_front_porch + panel->lcd_hbp + > > panel->lcd_x) and not timmings->hor_front_porch + panel->lcd_hbp + > > sync_width + panel->lcd_x > > No ie not true we can't include sync_width, please see here [1] > > timmings->hor_front_porch= panel_info->lcd_ht-panel_info->lcd_hbp - > panel_info->lcd_x; > panel_info->lcd_ht = timmings->hor_front_porch + panel_info->lcd_hbp + > panel_info->lcd_x; > > and the result of this lcd_ht is exactly matched with Mainline timings > or any supported panel in A64. > > [1] https://github.com/longsleep/linux-pine64/blob/pine64-hacks-1.2/drivers/video/sunxi/disp2/disp/de/disp_lcd.c#L1839 Can we please start to reason in actual timings instead of whatever Allwinner comes up with in their BSP? Maxime -- Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com --kz6w2pkvgsyb3k3x Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRcEzekXsqa64kGDp7j7w1vZxhRxQUCXKN2DgAKCRDj7w1vZxhR xSqeAQDx9BENI+4TJ3ci0QpZ7BjfMqO0Vh62flCE/SGh1xBZ1AEA90msbhYdW4kl QZEV8OU5fZZksH7oMSKF0v0/jry/Wwg= =fcSY -----END PGP SIGNATURE----- --kz6w2pkvgsyb3k3x-- --===============3953736402460800640== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel --===============3953736402460800640==--