Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935465AbdCLVKn (ORCPT ); Sun, 12 Mar 2017 17:10:43 -0400 Received: from pandora.armlinux.org.uk ([78.32.30.218]:47442 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934858AbdCLVKj (ORCPT ); Sun, 12 Mar 2017 17:10:39 -0400 Date: Sun, 12 Mar 2017 21:09:53 +0000 From: Russell King - ARM Linux To: Steve Longerbeam Cc: mark.rutland@arm.com, andrew-ct.chen@mediatek.com, minghsiu.tsai@mediatek.com, nick@shmanahar.org, songjun.wu@microchip.com, hverkuil@xs4all.nl, pavel@ucw.cz, shuah@kernel.org, devel@driverdev.osuosl.org, markus.heiser@darmarIT.de, Steve Longerbeam , robert.jarzmik@free.fr, geert@linux-m68k.org, p.zabel@pengutronix.de, linux-media@vger.kernel.org, devicetree@vger.kernel.org, kernel@pengutronix.de, arnd@arndb.de, tiffany.lin@mediatek.com, bparrot@ti.com, robh+dt@kernel.org, horms+renesas@verge.net.au, mchehab@kernel.org, laurent.pinchart+renesas@ideasonboard.com, linux-arm-kernel@lists.infradead.org, niklas.soderlund+renesas@ragnatech.se, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, jean-christophe.trotin@st.com, sakari.ailus@linux.intel.com, fabio.estevam@nxp.com, shawnguo@kernel.org, sudipm.mukherjee@gmail.com Subject: Re: [PATCH v5 00/39] i.MX Media Driver Message-ID: <20170312210952.GV21222@n2100.armlinux.org.uk> References: <1489121599-23206-1-git-send-email-steve_longerbeam@mentor.com> <20170312175118.GP21222@n2100.armlinux.org.uk> <191ef88d-2925-2264-6c77-46647394fc72@gmail.com> <20170312192932.GQ21222@n2100.armlinux.org.uk> <58b30bca-20ca-d4bd-7b86-04a4b8e71935@gmail.com> <20170312204037.GU21222@n2100.armlinux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170312204037.GU21222@n2100.armlinux.org.uk> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1919 Lines: 38 On Sun, Mar 12, 2017 at 08:40:37PM +0000, Russell King - ARM Linux wrote: > On Sun, Mar 12, 2017 at 01:36:32PM -0700, Steve Longerbeam wrote: > > But hold on, if my logic is correct, then why did the CSI power-off > > get reached in your case, multiple times? Yes I think there is a bug, > > link_notify() is not checking if the link has already been disabled. > > I will fix this. But I'm surprised media core's link_notify handling > > doesn't do this. > > Well, I think there's something incredibly fishy going on here. I > turned that dev_dbg() at the top of the function into a dev_info(), > and I get: > > root@hbi2ex:~# dmesg |grep -A2 imx-ipuv3-csi > [ 53.370949] imx-ipuv3-csi imx-ipuv3-csi.0: power OFF > [ 53.371015] ------------[ cut here ]------------ > [ 53.371075] WARNING: CPU: 0 PID: 1515 at drivers/staging/media/imx/imx-media-csi.c:806 csi_s_power+0xb8/0xd0 [imx_media_csi] > -- > [ 53.372624] imx-ipuv3-csi imx-ipuv3-csi.0: power OFF > [ 53.372637] ------------[ cut here ]------------ > [ 53.372663] WARNING: CPU: 0 PID: 1515 at drivers/staging/media/imx/imx-media-csi.c:806 csi_s_power+0xb8/0xd0 [imx_media_csi] > > There isn't a power on event being generated before these two power > off events. I don't see a power on event even when I attempt to > start streaming either (which fails due to the lack of bayer > support.) Found it - my imx219 driver returns '1' from its s_power function when powering up, which triggers a bug in your code - when imx_media_set_power() fails to power up, you call imx_media_set_power() telling it to power everything off - including devices that are already powered off. This is really bad news - s_power() may be called via other paths, such as when the subdev is opened. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net.