From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Subject: Re: [PATCH 2/2] HID: roccat: using new sysfs_create_bin_group() in
 kone driver
Date: Fri, 12 Nov 2010 22:06:34 -0800
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To: Greg KH <gregkh@suse.de>
Cc: Eric Biederman <ebiederm@aristanetworks.com>, Stefan Achatz <stefan_achatz@web.de>, "Serge E. Hallyn" <serue@us.ibm.com>, Tejun Heo <tj@kernel.org>, Jiri Kosina <jkosina@suse.cz>, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, Benjamin Thery <benjamin.thery@bull.net>

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 <stefan_achatz@web.de> 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].

-- 
Dmitry