From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Achatz Subject: Re: [PATCH 2/2] HID: roccat: using new sysfs_create_bin_group() in kone driver Date: Sat, 13 Nov 2010 17:34:15 +0100 Message-ID: <1289666055.2191.1.camel@neuromancer> References: <1289585921.2629.13.camel@neuromancer> <20101113005232.GA20865@suse.de> <20101113060634.GB1919@core.coreip.homeip.net> <20101113143908.GA29750@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20101113143908.GA29750@suse.de> Sender: linux-kernel-owner@vger.kernel.org To: Greg KH Cc: Dmitry Torokhov , Eric Biederman , "Serge E. Hallyn" , Tejun Heo , Jiri Kosina , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, Benjamin Thery List-Id: linux-input@vger.kernel.org Am Samstag, den 13.11.2010, 06:39 -0800 schrieb Greg KH: > On Fri, Nov 12, 2010 at 10:06:34PM -0800, Dmitry Torokhov wrote: > > On Fri, Nov 12, 2010 at 04:52:32PM -0800, Greg KH wrote: > > > On Fri, Nov 12, 2010 at 04:21:45PM -0800, Eric Biederman wrote: > > > > On Fri, Nov 12, 2010 at 10:18 AM, Stefan Achatz wrote: > > > > > hid-roccat-kone now uses new group functions for creating binary > > > > > sysfs attributes. > > > > > > > > Looking at this, I have a problem with the way this works. > > > > You are still doing this the hard and racy way. > > > > > > > > sysfs attributes that are only added when we initialize the hardware and > > > > are only removed when we remove the driver should use the device layer > > > > functions to create their attributes. > > > > > > > > This achieves two things. The code is easier to write because there > > > > is less of it. > > > > The notification to user space happens after the attributes appear so > > > > that you don't > > > > have strange hotplug races. > > > > > > > > If there a chance you can look at implementing this in the simpler > > > > race free way? > > > > > > Good point, just attach this attribute group to the device and the > > > driver core will automatically create the files for you. > > > > > > > Attribute group in device structure is normally owned and managed by > > subsystem core; without additional plumbing drivers should not be > > touching it, at least not normally. > > > > Plus we do not have binary attribute group in device structure [yet]. > > In thinking about it a bit more, why do you have so many binary > attributes for this driver? binary sysfs files are rare, so adding a > binary attribute group pointer to the device or driver would just waste > a lot of space that no one else uses. > > What are these binary files for? Who uses them? I don't seem to be > able to find them in the Documentation/ABI directory, or am I missing > something here? Documentation/ABI/testing/sysfs-driver-hid-roccat-kone Stefan