Connected PL2303 device run's out of serial devices at random minor numbers.
Mar 1 07:09:09 localhost kernel: [265922.934119] usb 5-1: USB disconnect, device number 83
Mar 1 07:09:10 localhost kernel: [265923.245580] usb 5-1: new full-speed USB device number 84 using sw-ohci
Mar 1 07:09:10 localhost kernel: [265923.451746] pl2303 5-1:1.0: pl2303 converter detected
Mar 1 07:09:10 localhost kernel: [265923.486633] pl2303 5-1:1.0: No more free serial devices
Mar 1 07:09:10 localhost kernel: [265923.496483] pl2303: probe of 5-1:1.0 failed with error -5
Mar 1 07:09:10 localhost mtp-probe: checking bus 5, device 84: "/sys/devices/platform/sw-ohci.2/usb5/5-1"
Mar 1 07:09:10 localhost mtp-probe: bus: 5, device: 84 was not an MTP device
Connected PL2303 device run's out of serial devices at random minor numbers.
Mar 1 07:09:09 localhost kernel: [265922.934119] usb 5-1: USB disconnect, device number 83 Mar 1 07:09:10 localhost kernel: [265923.245580] usb 5-1: new full-speed USB device number 84 using sw-ohci Mar 1 07:09:10 localhost kernel: [265923.451746] pl2303 5-1:1.0: pl2303 converter detected Mar 1 07:09:10 localhost kernel: [265923.486633] pl2303 5-1:1.0: No more free serial devices Mar 1 07:09:10 localhost kernel: [265923.496483] pl2303: probe of 5-1:1.0 failed with error -5 Mar 1 07:09:10 localhost mtp-probe: checking bus 5, device 84: "/sys/devices/platform/sw-ohci.2/usb5/5-1" Mar 1 07:09:10 localhost mtp-probe: bus: 5, device: 84 was not an MTP device
The kernel group thread can be found here. http://marc.info/?l=linux-usb&m=146846787217550&w=2