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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 3A960C32751 for ; Wed, 7 Aug 2019 12:06:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 179B4219BE for ; Wed, 7 Aug 2019 12:06:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729551AbfHGMGn (ORCPT ); Wed, 7 Aug 2019 08:06:43 -0400 Received: from retiisi.org.uk ([95.216.213.190]:41176 "EHLO hillosipuli.retiisi.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726773AbfHGMGn (ORCPT ); Wed, 7 Aug 2019 08:06:43 -0400 Received: from valkosipuli.localdomain (valkosipuli.retiisi.org.uk [IPv6:2a01:4f9:c010:4572::80:2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by hillosipuli.retiisi.org.uk (Postfix) with ESMTPS id 750D9634C87; Wed, 7 Aug 2019 15:06:27 +0300 (EEST) Received: from sailus by valkosipuli.localdomain with local (Exim 4.92) (envelope-from ) id 1hvKi2-0000Wl-VU; Wed, 07 Aug 2019 15:06:26 +0300 Date: Wed, 7 Aug 2019 15:06:26 +0300 From: Sakari Ailus To: Ezequiel Garcia Cc: Philipp Zabel , Fabio Estevam , hverkuil@xs4all.nl, slongerbeam@gmail.com, linux-imx@nxp.com, linux-media@vger.kernel.org, kernel@pengutronix.de, shawnguo@kernel.org, mchehab@kernel.org Subject: Re: [PATCH v3] media: imx: mipi csi-2: Don't fail if initial state times-out Message-ID: <20190807120626.GE822@valkosipuli.retiisi.org.uk> References: <20190627222912.25485-1-festevam@gmail.com> <1561963729.3753.5.camel@pengutronix.de> <8b859fd7758c3f95b45b5b70909be0d2ae2e4f34.camel@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8b859fd7758c3f95b45b5b70909be0d2ae2e4f34.camel@collabora.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org On Tue, Jul 30, 2019 at 05:14:24AM -0300, Ezequiel Garcia wrote: > Hey Hans, > > On Mon, 2019-07-01 at 08:48 +0200, Philipp Zabel wrote: > > On Thu, 2019-06-27 at 19:29 -0300, Fabio Estevam wrote: > > > From: Ezequiel Garcia > > > > > > Not all sensors will be able to guarantee a proper initial state. > > > This may be either because the driver is not properly written, > > > or (probably unlikely) because the hardware won't support it. > > > > > > While the right solution in the former case is to fix the sensor > > > driver, the real world not always allows right solutions, due to lack > > > of available documentation and support on these sensors. > > > > > > Let's relax this requirement, and allow the driver to support stream start, > > > even if the sensor initial sequence wasn't the expected. > > > > > > Also improve the warning message to better explain the problem and provide > > > a hint that the sensor driver needs to be fixed. > > > > > > Signed-off-by: Ezequiel Garcia > > > Signed-off-by: Fabio Estevam > > > > Reviewed-by: Philipp Zabel > > > > This seems ready to pick and it has Philipp's and Steve's RB. Hi Ezequiel, In general the LP-11 condition should be detected by hardware (or firmware) in such a way that it's detected even if a transmitter that holds the state just a short period of time. In other words, software is not supposed to be even testing for it. Have you checked how it works if you simply leave out this test? I remember that there has been hardware that does indeed require further initialisation done only *after* LP-11 has been detected by _software_. -- Regards, Sakari Ailus