From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anssi Hannula Subject: Re: sysfs change of input/event devices in 2.6.23rc breaks udev Date: Sat, 15 Sep 2007 18:46:19 +0300 Message-ID: <46EBFE4B.7000002@gmail.com> References: <46E2D712.1010402@gmail.com> <20070915010519.34bcb9ae.akpm@linux-foundation.org> <200709151018.16076.dtor@insightbb.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <200709151018.16076.dtor@insightbb.com> Sender: owner-linux-input@atrey.karlin.mff.cuni.cz List-Help: List-Owner: List-Post: List-Unsubscribe: To: Dmitry Torokhov Cc: Andrew Morton , Greg KH , Kay Sievers , linux-input@atrey.karlin.mff.cuni.cz, linux-kernel@vger.kernel.org List-Id: linux-input@vger.kernel.org Dmitry Torokhov wrote: > On Saturday 15 September 2007 04:05, Andrew Morton wrote: >> On Mon, 10 Sep 2007 09:24:04 -0400 "Dmitry Torokhov" wrote: >> >>> On 9/10/07, Greg KH wrote: >>>> On Mon, Sep 10, 2007 at 01:28:47AM -0400, Dmitry Torokhov wrote: >>>>> On Sunday 09 September 2007 19:03, Kay Sievers wrote: >>>>>> On 9/8/07, Anssi Hannula wrote: >>>>>>> However, the change that broke id_path of udev is that >>>>>>> /sys/class/input/event5/device is now a symlink to the inputX directory >>>>>>> instead of being the same as the device symlink in inputX directory, >>>>>>> i.e. to ../../../devices/platform/pcspkr in this case. >>>>>>> >>>>>>> Udev id_path uses that directory to construct the ID_PATH variable. >>>>>>> Should the sysfs structure be reverted or should udev be adapted to >>>>>>> handle traversing /device symlink twice? I think the former, as there >>>>>>> should be considerably more time to adapt udev for coming changes in sysfs. >>>>>> Udev's path_id script is too dumb to follow the "device" link of >>>>>> stacked class devices in the CONFIG_SYSFS_DEPRECATED=y layout. Does >>>>>> this change fix it for you? >>>>>> http://git.kernel.org/?p=linux/hotplug/udev.git;a=commitdiff_plain;h=b1ac36ff5e3756cefc79967a26280056da31bf6f >>>>>> >>>>> Hmm, fixing udev is good but users will not get the change in time. I think we >>>>> need to adjust SYSFS_DEPRECATED code to produce old results. Something like the >>>>> patch below. I wonder what Greg would think... >>>> Hm, I don't understand. Didn't the original conversion of the input >>>> layer by Kay not have this kind of problem? What did your changes do >>>> differently to cause this driver core change to be needed? >>>> >>> If I understand it correctly Kay's convesion had the same issue. With >>> class devices "device" link points to class_dev->device instead of >>> class_dev->parent. If you want to keep compatibility with old sysfs >>> layout when moving from class devices to regular devices then you need >>> to "skip" couple of parents till you get to "real" device. This only >>> matters for input because this was the only subsystem with class >>> devices stacked. >>> >> > > Limbo ;) > > Anssi, could you please tell me if the patch fixes the issue on your box? It does. >> Did this userspace-visible post-2.6.22 regression get fixed? >> > > I'd like the patch to go through Greg if he is OK with it. > -- Anssi Hannula