From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jon Smirl Date: Sat, 30 Jul 2005 14:24:38 +0000 Subject: Re: multiseat Message-Id: <9e47339105073007241a9a064f@mail.gmail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: linux-hotplug@vger.kernel.org Greg, is USB numbering unstable across reboot, if so can we fix it?=20 Is it possible to use USB port number like, 2-2.3:1.0, to stably assign mouse0, mouse1, etc? Same for keyboards. This is part of the console group problem I talked about earlier. The base system really needs to support this so that we don't rebuild it in each app. On 7/30/05, Daniel Stone wrote: > On Sat, Jul 30, 2005 at 12:57:35AM -0400, Jon Smirl wrote: > > On 7/29/05, Daniel Stone wrote: > > > On Thu, Jul 28, 2005 at 11:06:24AM -0400, Jon Smirl wrote: > > > > Check out udev. It addresses your complaints about USB renumbering. > > > > > > No, it really does not, especially across reboots. We found that the > > > only way to actually preserve your devices was to have a /dev/multise= at > > > directory controlled by a daemon which gets kicked by hotplug events, > > > and then uses some hand-wavey heuristics to try to work out which mou= se > > > it is. > > > > The USB port numbers like 2-2.3:1.0 are consistent across reboots > > unless you move the wires around. Does that work to assign the mouseX > > dev node? Are there more specific problems? Maybe they can be fixed in > > udev. >=20 > I don't udev keeps the mapping consistent, necessarily. This is why we > wrote our own userspace scripts and configuration files to keep policy. >=20 > > This is a good argument for the one hub per seat scheme. You would > > track the hubs and then assign anything plugged into them to the user. > > Since mice/keyboards are interchangeable you don't need to track the > > via a serial number. >=20 > Most keyboards are USB hubs, which makes things a little more > convenient, but as I said before, you do not get guaranteed numbering > across reboots. >=20 > Multiseat is not trivial. It does not work out of the box on a standard > system. It takes a lot of effort to get it working out of the box when > you have a configurator that works out which keyboards and mice are > where (via polling all the relevant event devices and saying 'now press > some keys on keyboard three'), and you have your own policy helpers. > With carefully selected cards. Even then you get fun like everything > works fine if you kick the primary card first and then the three ones > that aren't decoding VGA, but fails when you don't do the primary card > first. >=20 > It would be nice if we fixed all the drivers to not be so VGA-centric, > and if udev kept numbering for the same devices vaguely consistent > across reboots, etc, etc. And it would all be useful work. But it does > not work out of the box, and won't any time soon. >=20 --=20 Jon Smirl jonsmirl@gmail.com ------------------------------------------------------- SF.Net email is sponsored by: Discover Easy Linux Migration Strategies from IBM. Find simple to follow Roadmaps, straightforward articles, informative Webcasts and more! Get everything you need to get up to speed, fast. http://ads.osdn.com/?ad_idt77&alloc_id=16492&op=CCk _______________________________________________ Linux-hotplug-devel mailing list http://linux-hotplug.sourceforge.net Linux-hotplug-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel