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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=IV8bvWGwdnJJNtKbipz1NamC8B6NKiQzt7b7JGCJg9A=; b=jrDjOa8JshXRhAix94ourJhoc 9rJd9hbfUBW4hs+nUWbS0YkTEvuaLWNYfV4PqXnzWxV5ptY5hTL0RLa7nKVmL6/mJElg/X/u2n2hU I88zd+fq0D0YL9BSvRr/27txDycMcoCjfloeRS1YTwOS56HHXUh1B3lwvQlZIVLBwc8Rs1EKFOJBb wp6e78nZj0zvhFYGBFHhSn1I70/E+waPLkQ9FYoHZ4bjaZJ1isbWW2CnS4zpbledpdW+WNkO0whIi jhThJ1FPwPFYpA6/EnwOZuSJIq6Jdw8ZHCvnZoRXrFQKBUyMlKXdLx7v5wtLblNZqgtFH9HwRNZmU SbS+JvWzg==; 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 1h6Bw8-0006Tc-7y; Tue, 19 Mar 2019 10:25:36 +0000 Received: from relay4-d.mail.gandi.net ([217.70.183.196]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1h6Bw2-0006Md-DK for linux-arm-kernel@lists.infradead.org; Tue, 19 Mar 2019 10:25:33 +0000 X-Originating-IP: 90.88.22.102 Received: from localhost (aaubervilliers-681-1-80-102.w90-88.abo.wanadoo.fr [90.88.22.102]) (Authenticated sender: maxime.ripard@bootlin.com) by relay4-d.mail.gandi.net (Postfix) with ESMTPSA id 542CBE0011; Tue, 19 Mar 2019 10:25:21 +0000 (UTC) Date: Tue, 19 Mar 2019 11:25:20 +0100 From: Maxime Ripard To: Jagan Teki Subject: Re: [PATCH v8 01/15] drm/sun4i: dsi: Fix video start delay computation Message-ID: <20190319102520.ldgjtyzrphuib3td@flea> References: <20190311133637.18334-1-jagan@amarulasolutions.com> <20190311133637.18334-2-jagan@amarulasolutions.com> <20190311153734.izg44ijwqqh2vpxc@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-20190319_032530_778036_95E70C2B X-CRM114-Status: GOOD ( 23.05 ) 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: Mark Rutland , devicetree , David Airlie , Michael Turquette , linux-sunxi , linux-kernel , dri-devel , Chen-Yu Tsai , Rob Herring , Daniel Vetter , Michael Trimarchi , linux-amarula@amarulasolutions.com, linux-clk , linux-arm-kernel Content-Type: multipart/mixed; boundary="===============1290324762542467255==" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org --===============1290324762542467255== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="4kxxtlmvi7tknwsq" Content-Disposition: inline --4kxxtlmvi7tknwsq Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Mon, Mar 11, 2019 at 09:31:11PM +0530, Jagan Teki wrote: > On Mon, Mar 11, 2019 at 9:07 PM Maxime Ripard wrote: > > > > On Mon, Mar 11, 2019 at 07:06:23PM +0530, Jagan Teki wrote: > > > Vertical video start delay is computed by excluding vertical front > > > porch value from total vertical timings. > > > > > > This clearly confirmed from BSP code and here how it computed, > > > > > > (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 > > > > > > But the current driver is assuming it can exclude vertical front > > > porch along with vertical sync values from total vertical timings, > > > which resulting wrong start delay indeed wrong picture rendering > > > in the panel. > > > > Same story here: which panel, which datasheet, which "wrong picture > > rendering"? > > It's bananapi,s070wv20-ct16 DSI You're answering one out of three questions. > > > Example: timings, where it produces the issue. > > > { > > > .vdisplay = 600, > > > .vsync_start = 600 + 12, > > > .vsync_end = 600 + 12 + 2, > > > .vtotal = 600 + 12 + 2 + 21, > > > } > > > > Can you 100% trust those timings? > > ie. reason, I have given the Mainline timings [1]. The above timings > are wrongly mentioned actual timings are from [1] You're still answering partially here. Those timings are working for RGB, you have no proof that we need to make the same adjustments for DSI. > > > It produces the desired start delay value as 19 but the correct working > > > value should be 513. > > > > > > So, Fix it by computing proper video start delay. > > > > > > Fixes: 69006ef0ecb1 ("drm/sun4i: dsi: Change the start delay calculation") > > > Signed-off-by: Jagan Teki > > > --- > > > drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 10 ++++++++-- > > > 1 file changed, 8 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c > > > index 62a508420227..8d6292c0158b 100644 > > > --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c > > > +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c > > > @@ -364,8 +364,14 @@ static void sun6i_dsi_inst_init(struct sun6i_dsi *dsi, > > > static u16 sun6i_dsi_get_video_start_delay(struct sun6i_dsi *dsi, > > > struct drm_display_mode *mode) > > > { > > > - u16 start = clamp(mode->vtotal - mode->vdisplay - 10, 8, 100); > > > - u16 delay = mode->vtotal - (mode->vsync_end - mode->vdisplay) + start; > > > + u16 delay = mode->vtotal - (mode->vsync_start - mode->vdisplay); > > > + > > > + /** > > > + * BSP comment: > > > + * put start_delay to tcon. set ready sync early to dramfreq, > > > + * so set start_delay 1 > > > + */ > > > > That doesn't make any sense to me... What does it mean? > > Which is meaning as above stated as "BSP comment" from here[2] It doesn't matter where you took it from. If you cannot explain what happen, putting a random label that doesn't explain anything will not help. Maxime -- Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com --4kxxtlmvi7tknwsq Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRcEzekXsqa64kGDp7j7w1vZxhRxQUCXJDDkAAKCRDj7w1vZxhR xU+WAP0bWohQTOy2V10s8wo9M2tCtIwFTHk6g2vFYaoClQVpdAEA48ghCZuiSvUd 2pSL7z54qV6CklWr3sxeK3Mixv1nwwI= =hFp+ -----END PGP SIGNATURE----- --4kxxtlmvi7tknwsq-- --===============1290324762542467255== 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 --===============1290324762542467255==--