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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1760FC19F28 for ; Wed, 3 Aug 2022 05:56:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233897AbiHCF4a (ORCPT ); Wed, 3 Aug 2022 01:56:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49150 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231898AbiHCF41 (ORCPT ); Wed, 3 Aug 2022 01:56:27 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5153BDFDA for ; Tue, 2 Aug 2022 22:56:25 -0700 (PDT) Received: from ptx.hi.pengutronix.de ([2001:67c:670:100:1d::c0]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1oJ7Md-0008G4-Fm; Wed, 03 Aug 2022 07:56:15 +0200 Received: from mfe by ptx.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1oJ7MQ-0000Ia-QS; Wed, 03 Aug 2022 07:56:02 +0200 Date: Wed, 3 Aug 2022 07:56:02 +0200 From: Marco Felsch To: Adam Ford Cc: Fabio Estevam , Marek Vasut , Stefan Agner , Jernej Skrabec , Daniel Vetter , Jonas Karlman , David Airlie , dri-devel , Neil Armstrong , NXP Linux Team , Robert Foss , Linux Kernel Mailing List , Pengutronix Kernel Team , Laurent Pinchart , Andrzej Hajda , Marek Szyprowski , Shawn Guo , Sascha Hauer , arm-soc , Jagan Teki , robert.chiras@nxp.com, laurentiu.palcu@nxp.com Subject: Re: imx8mm lcdif->dsi->adv7535 no video, no errors Message-ID: <20220803055602.b5x7ekgm54x45r5n@pengutronix.de> References: <20220801225538.qtdb5zd66g6ipewz@pengutronix.de> <20220802080820.jyf3tfpgcj3pvbtp@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c0 X-SA-Exim-Mail-From: mfe@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Adam, sorry for the delay. On 22-08-02, Adam Ford wrote: ... > > > I think that the most important one is the blanking calc. Can you try to > > > revert "drm/bridge: adv7511: Repair bus_flags and bus_format" and check > > > if you can get a output still? Also something to try would be to disable > > > the internal timing generator by specifying > > > 'adi,disable-timing-generator'. Also if you have an oscilloscope for > > I did some reading about the internal timing generator. It appears > that it's required when video formats use fractional bytes, and it's > preconfigured to run at 720p by default, but registers 28h through 37h > configure it for other video modes. I thought this timing generator can detect the sync timing automatically. Also I saw some mail discussions where this timing generator can trigger missbehaviours. Since we send the sync packages from the dsi-host to the ADV, I think it should be possible for the ADV to reconstruct the sync signals without the need of the internal timing generator. > Are you thinking the imx8mm DSI generator would do it better? You mean the porches we are sending? Regards, Marco