From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kay Sievers Date: Tue, 13 Oct 2009 08:22:34 +0000 Subject: Re: group is not set properly for usb printer for older kernels Message-Id: List-Id: References: <20091008191201.19276c15@workstation64.home> In-Reply-To: <20091008191201.19276c15@workstation64.home> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: linux-hotplug@vger.kernel.org On Tue, Oct 13, 2009 at 05:30, Evangelos Foutras wrot= e: > I set udev's loglevel to "debug" and saw something interesting in my logs > [1] after turning on the printer. Specifically, the following line appears > to be of interest: > > =C2=A0Oct 12 19:38:26 foutboxd udevd-work[7541]: '/lib/udev/usb_id' (stde= rr) > 'error opening USB device 'descriptors' file' > > Maybe the 'descriptors' file hasn't been created when the udev rules fire= ? I > think this would explain why subsequent calls to udevadm test/trigger app= ly > the correct group to the printer. Yes, that might be. There have been numerous fixes to recent kernel versions to address issues like this. You could try to set up rules with WAIT_FOR_SYSFS=3D"..." to possibly work around that on older kernel versions. The real fix though, is to run a kernel that matches the time the system-level tools are developed and used with in the major distros. Only these combinations are well tested and debugged. Mixing older kernel versions with newer system-level tools usually works fine, but there are many things that can go wrong, because nobody really tests the combinations in this direction. People usually only make sure, that newer kernels run on older systems, not the other way around. Kay