On Tue, Oct 20, 2015 at 05:20:23PM +0200, Erwin Van de Velde wrote: > Hi all, > > Due to some hardware issues, I have to reset USB modems and a USB to > serial converter on some of my servers. What I noticed is that > /dev/ttyUSBXX devices are never reused: ttyUSB1 becomes ttyUSB3 e.g. > and so on. This looks fine, but we have to do it rather often, so > after a while we reach ttyUSB511 after which the system refuses to > create new ttyUSB devices (I guess this is a hard limit in the kernel > code). > > This issue seems unsolvable with anything less than a reboot. Is there > a better way? Why are ttyUSB device numbers of devices that have > already disappeared not reused? Userspace still has the port open, so the number is not reused until userspace closes the device node. Fix your userspace programs to properly listen to the hangup signal to know to release the device node and you should be fine. > Tested on Debian 8 with 3.16 kernel. As Johan said, this is very old, please try a modern kernel. If you are stuck with Debian's kernel, please file a bug with them, there's nothing we can do here. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
