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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 CB929C43461 for ; Mon, 7 Sep 2020 09:44:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 83A0620C09 for ; Mon, 7 Sep 2020 09:44:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728411AbgIGJoy (ORCPT ); Mon, 7 Sep 2020 05:44:54 -0400 Received: from mga17.intel.com ([192.55.52.151]:63006 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726301AbgIGJox (ORCPT ); Mon, 7 Sep 2020 05:44:53 -0400 IronPort-SDR: NfV8bAzqUmFxHLhTa2RjSMqHW9ZKzZH7aQzKu3U7JRscsWvsfwL4Ts1gPobTuUcRopF7s34iu2 dPDzr4a80SYw== X-IronPort-AV: E=McAfee;i="6000,8403,9736"; a="138029841" X-IronPort-AV: E=Sophos;i="5.76,401,1592895600"; d="scan'208";a="138029841" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Sep 2020 02:44:53 -0700 IronPort-SDR: 7zItED0iAsj5DaPtscIu7g4BqbCXycUO8tAPBv+jvXAjZWnjiubQzrBKFpgjDms44IwKl9CUCu pWNhY+nD8xhA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.76,401,1592895600"; d="scan'208";a="333114514" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by orsmga008.jf.intel.com with ESMTP; 07 Sep 2020 02:44:50 -0700 Received: from andy by smile with local (Exim 4.94) (envelope-from ) id 1kFDhg-00EuZz-A3; Mon, 07 Sep 2020 12:44:48 +0300 Date: Mon, 7 Sep 2020 12:44:48 +0300 From: Andy Shevchenko To: Daniel Scally , Tsuchiya Yuto Cc: linux-media@vger.kernel.org, sakari.ailus@linux.intel.com, heikki.krogerus@linux.intel.com, Kieran Bingham , jorhand@linux.microsoft.com Subject: Re: cio2 ipu3 module to automatically connect sensors via swnodes Message-ID: <20200907094448.GS1891694@smile.fi.intel.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org +Cc: Surface community people. On Sat, Sep 05, 2020 at 09:19:51AM +0100, Daniel Scally wrote: > > Following on from this thread: > https://www.spinics.net/lists/linux-driver-devel/msg135122.html - > apologies, can't see a way to reply to it directly. Use lore [5] and its feature of downloading mailbox (or just seeing Message-Id which is enough for good MUA to attach reply properly to the thread). [5]: https://lore.kernel.org/linux-media/12fbe3f5c6a16c5f3447adbc09fe27ceb2b16823.1589625807.git.mchehab+huawei@kernel.org/ > Myself and others [1] have been trying to get cameras working on > Microsoft Surface and similar platforms, currently I'm working on > expanding Jordan's module connecting cameras to the cio2 > infrastructure (which works - we can use it to take images), aiming to > discover connection information from SSDB in the DSDT, as well as > connect as many supported sensors as are found on the device. I'm just > struggling with a problem I've encountered using the swnode patch that > Heikki linked in that thread; the module's working ok when I only > attempt to connect a single one of my sensors (by preventing the > driver for the other sensor from loading, in which case this new > module ignores the sensor), but when I attempt to connect both cameras > at the same time I get a kernel oops as part of > software_node_get_next_child. The module is creating software_nodes > like this... > > /sys/kernel/software_node/INT343E/port0/endpoint0 > /sys/kernel/software_node/INT343E/port1/endpoint0 > /sys/kernel/software_node/OVTI2680/port0/endpoint0 > /sys/kernel/software_node/OVTI5648/port0/endpoint0 > > And that's the structure that I expect to see, but it seems like the > call to list_next_entry in that function is returning something that > isn't quite a valid swnode. Printing the address of c->fwnode after > that point returns "3", which isn't a valid address of course, and > that's causing the oops when it's either returned (in the version of > the function without the patches) or when the program flow tries to > call the "get" op against that fwnode (in the patched version). I've > been trying to track it down for a while now without success, so I > posted the problem on SO[2] and it was suggested that I mail these > addressees for advice - hope that that is ok. > > > My copy of Jordan's module is parked in my git repo [3] for now, and > requires a batch of patches from Jordan's repo [4] (one made by Heikki > to fill in the missing swnode graph pieces, and some further tweaks) - > I've been applying those against 5.8.0-rc7. Any other criticism more > than welcome - I'm new to both c and kernel programming so I'm happy > to take all the advice people have the time to give. > > > On a more general note; Kieran from the libcamera project suggested we > ought to be talking to you guys anyway to get some guidance on design, > and some more expert eye on the things we don't really understand. In > particular; we haven't been able to figure out how sensors that are > intended to work with the cio2 ipu3 stuff have their clock/regulators > supplied - in fact I can strip all the "usual" clock/regulator > functionality out of my camera's driver and it still functions fine, > which seems a bit weird. So far all we're doing as "power management" > of the camera's is turning on the GPIO pins that DSDT tables assign to > the tps68470 PMICs the cameras are theoretically hooked up to...but > given the drivers continue to work without using the PMICs regulator > and clk drivers (which we found in the intel-lts tree on Github), > we're a bit confused exactly how these are connected. Given the > potential for actual hardware damage if we mess something up there > it'd be great if anyone can shed some light on those elements. > [1] https://github.com/linux-surface/linux-surface/issues/91 > [2] https://stackoverflow.com/questions/63742967/what-is-causing-this-kernel-oops-when-parsing-firmware? > [3] https://github.com/djrscally/miix-510-cameras/blob/master/surface_camera/surface_camera.c > [4] https://github.com/jhand2/surface-camera/tree/master/patches -- With Best Regards, Andy Shevchenko