Date: Sun, 8 Oct 2006 19:10:04 -0500 From: Karl Denninger <karl@denninger.net> To: Matthias Andree <matthias.andree@gmx.de> Cc: freebsd-stable@freebsd.org Subject: Re: Recommendations for a serial port card you can actually BUY? Message-ID: <20061009001004.GA85228@FS.denninger.net> In-Reply-To: <m3ac46yjvv.fsf@merlin.emma.line.org> References: <20061005151925.GA1156@FS.denninger.net> <20061005190822.GA15547@icarus.home.lan> <20061005202144.GA11105@FS.denninger.net> <54db43990610051404x1816135ft9740ec29eb5da23@mail.gmail.com> <20061006000909.GB2473@FS.denninger.net> <20061006135019.L76485@server.arg.sj.co.uk> <20061006175313.GA58888@FS.denninger.net> <m38xjs4iq5.fsf@merlin.emma.line.org> <20061007234746.GA31286@FS.denninger.net> <m3ac46yjvv.fsf@merlin.emma.line.org>
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On Sun, Oct 08, 2006 at 04:14:44PM +0200, Matthias Andree wrote: > Karl Denninger <karl@denninger.net> writes: > > > Uh, if you unplug a working serial device's USB cable, you've got bigger > > problems :) > > So you think? USB is hotplug, and it doesn't have to be a port in use > that you're unplugging. I realize that but my point is that if you unplug a serial port that has a process connected to it you're going to yank its file descriptor out from under it, and it will not be pleased about that! > > If you plug and unplug ONLY ONE, it should ID in the same place, since > > there's a "hole". If you plug / unplug more than one, I can live with the > > penalty being a required reboot. After all, these are NOT supposed to be > > tampered with while the machine is running! > > OK, that makes things easier. > > Perhaps un-/reloading the kernel driver modules (if compiled as module) > is sufficient anyways -- the module will probably reprobe everything upon > reload; OTOH you can check usbd and devd and things if you can pin > devices to certain ordering. I'm likely going to have a shell script that runs at boot and creates a "local device" directory with symlinks to the ucom ports involved, based on their physical location. This way Device #1 that is connected to USB Serial Adapter #1 can always open /ldev/usb-serial1 and GET the first USB serial device (plugged into the first physical USB port), no matter in what order they identify. -- -- Karl Denninger (karl@denninger.net) Internet Consultant & Kids Rights Activist http://www.denninger.net My home on the net - links to everything I do! http://scubaforum.org Your UNCENSORED place to talk about DIVING! http://genesis3.blogspot.com Musings Of A Sentient Mind
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