I'm connecting a Nokia 6230i phone with a USB cable. After telling the phone not to behave as a USB Storage device, it appears as a USB Serial device. The nokia_dku2 module (source attached) makes sure the right endpoint is used, but otherwise the 'generic' usbserial is used. When the device resets, either when it spontaneously reboots due to an invalid command I send it (with gnokii) or when I intentionally press its Power button and shut it down (in an ordely fashion), the kernel hangs shortly after. This doesn't appear to be affected by usbserial being operational (performing reads/writes) at that point. When I perform writes which cause the device to spontaneously reboot, the hang comes few seconds after it reports the device's ETIMEOUT (-110) and then disconnection; I even managed to enter a few characters on the console before it hung tight (magic-sysrq was on and alt-sysrq-p had no effect).
I don't see the source attached.
Actually, I figured out: 1. I don't need usbserial loaded to reproduce the problem. 2. I don't need ohci-hcd loaded to reproduce the problem. so that pretty much makes it a hardware problem of mine, thus INVALID. BTW, There's some wicked stuff happening when the phone shuts down, ranging from system hangs to my SATA hard-drive suddenly stopping operations, sata_nv complaining one of the ports returns unexpected data (and resuming operating just fine after a reboot).