From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754874Ab0KMOsL (ORCPT ); Sat, 13 Nov 2010 09:48:11 -0500 Received: from cantor2.suse.de ([195.135.220.15]:59249 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753976Ab0KMOsH (ORCPT ); Sat, 13 Nov 2010 09:48:07 -0500 Date: Sat, 13 Nov 2010 06:39:08 -0800 From: Greg KH To: Dmitry Torokhov Cc: Eric Biederman , Stefan Achatz , "Serge E. Hallyn" , Tejun Heo , Jiri Kosina , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, Benjamin Thery Subject: Re: [PATCH 2/2] HID: roccat: using new sysfs_create_bin_group() in kone driver Message-ID: <20101113143908.GA29750@suse.de> References: <1289585921.2629.13.camel@neuromancer> <20101113005232.GA20865@suse.de> <20101113060634.GB1919@core.coreip.homeip.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20101113060634.GB1919@core.coreip.homeip.net> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? thanks, greg k-h