On Sun, 22 Nov 2009, Simon Arlott wrote: > On 21/11/09 23:28, Alan Stern wrote: > > On Sat, 21 Nov 2009, Simon Arlott wrote: > >> It just suddenly stopped at "usb 4-2.4.4.4: new full speed USB > >> device using ohci_hcd and address 107". > > > > If all those intermediate hubs are bus-powered, that's not at all > > surprising. > > They are, and they all pretend to be self-powered, but it shouldn't > cause a deadlock situation. I couldn't resolve it even by unplugging > all devices from that host controller. Tracking down the deadlock will require more information. A kernel log with CONFIG_USB_DEBUG certainly, and a usbmon trace if you can get it. > > You are allowed to have up to six links in the chain, that is, a device > > plugged into five hubs (provided you don't violate the rule about no > > plugging one bus-powered hub into another). > > I keep seeing conflicting information, sometimes claiming that the > host itself counts within the "five" hubs rule. If you count the host itself then you're allowed six hubs. The description in the spec is "seven-tiers". 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
