On Wed, 14 Jul 2010, Leandro Melo de Sales wrote: > Hi Toan and others, > My computer is not hanging anymore when I disable the 7-0:1.0 bus: > > cd /sys/module/usbcore/drivers/usb:hub/ > echo -n '7-0:1.0' > unbind > > ... it seems that it is better working now. Is there any drawback doing > this? Maybe it is a conflict problem between modules, I mean, a conflict > between ehci_hcd and uhci_hcd? since 7-0:1.0 is being controlled by the > uhci_hcd. There shouldn't be any conflict. ehci-hcd is used only for high-speed devices (480 Mb/s) whereas uhci-hcd is used only for full-speed (12 Mb/s) and low-speed (1.5 Mb/s) devices. > How to better solve this? How can I make my kernel (ubuntu 10.04) > to persist the command above during the boot process? You can add the command to a startup file such as /etc/rc.d/rc.local. A better command to use would be: echo -n '0000:00:1d.1' >/sys/bus/pci/drivers/uhci_hcd/unbind > My laptop has only two external usb ports, as following: > > Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub > *** Problematic *** -->> Bus 007 Device 001: ID 1d6b:0001 Linux Foundation > 1.1 root hub > Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub > Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub > Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub > Bus 003 Device 004: ID 0930:0508 Toshiba Corp. Integrated Bluetooth HCI > Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub > Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub > Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub > > How can I know that device is plugged in the Bus 007? Boot the earlier, working kernel and then see what lsusb says. Probably bus 7 is not connected to the computer's external USB ports but it is used only for internal devices like the fingerprint reader and webcam. > I plugged devices > in both ports and from lsusb I noticed that the bus used by the devices was > usb 6-1 and usb 8-2. As can be noticed above, the Bluetooth HCI device is > attached to Bus 003 Device 004 (is this mean 3-4?) No. 3-4 means bus 3 port 4, not bus 3 device 4. > and in addition to this I > have a built-in webcam and a fingerprint reader, what probably are causing > the problem. I accessed the bios and disabled the webcam, the problem > persists, and I didn't find any option to disable the fingerprint reader. Do > you think that the problem is with fingerprint reader? I have only Linux > installed on my Toshiba M750 Portege laptop. Quite likely the fingerprint reader is the cause of the problem. > The lsusb -v output for the bus 007 is shown next. Is is possible to > take any conclusion from the output below? No, not really. Those values are all normal. > How can I isolate Bus 007 and > make kernel ignore it during the OS startup? I don't know of any way to do that. That command I mentioned above comes close, but obviously you can't use it until after the system has already started. You should try Toan's suggestion about increasing the value in /sys/module/usbcore/parameters/initial_descriptor_timeout. Maybe 5000 is too low for the fingerprint reader. 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
