On Thu, 2 Apr 2009, [UTF-8] David Jaša wrote: > I've did some usbmon logging with three various flash disks - quite > old 256MB Jogr and two recent ones: 4GB Kingston and 8GB A-Data. I > logged it this way: I disconnected all USB devices from ports. Then I > started "cat /sys/kernel/debug/usbmon/0u" with output redirected to > separate files, plugged in the usb stick, waited for around 60 secs, > then removed the stick and stopped cat. I did this twice for each of > drives. I've attached resulting as files with 1 and 2 in their names. The traces don't show exactly what is wrong. All that happens is every time the EHCI port is reset, the connection drops. To the kernel, it appears as if the device was unplugged. It's possible that the kernel was trying to hand the device over to the UHCI controller but failed. There may be more useful information in the dmesg log if you build a kernel with CONFIG_USB_DEBUG enabled. > To make things more funny (at least for me) the drives sometimes were > sometimes found and mounted. I needed around 10 tries for each drive > to record usbmon log of such succesful mount. They were mounted some > twenty seconds after plugging in. These tries are logged *3.mon.out > files. In each of those cases the device was successfully handed to the UHCI controller. Alan Stern -- 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
