On Wed, 11 Jul 2012, Paul Menzel wrote: > Dear Alan, > > > as always thank you very much for answering to my problem reports. > > > Am Mittwoch, den 04.07.2012, 21:25 -0400 schrieb Alan Stern: > > On Thu, 5 Jul 2012, Paul Menzel wrote: > > > > an USB Logitech keyboard > > > > > > Bus 004 Device 003: ID 046d:c30f Logitech, Inc. Logicool HID-Compliant Keyboard (106 key) > > > > > > arbitrarily gets unresponsive on my system and stays this way. > > > > > > I am working in X and suddenly nothing entered to the keyboard has an > > > effect. I cannot switch to a virtual terminal with Ctrl + Alt + F<n>, n > > > ∈ ℕ, but the LEDs of the keyboard are still lighted. The USB mouse keeps > > > working though. > > > > > > After plugging it out and back in it works again. > > > > > > The distribution is Debian Sid/unstable with Linux 3.2 and it happened > > > with two mainboards, the ASUS M2A-VM [1] and ASRock A780FullHD [2]. > > > > Is the keyboard attached to an xHCI controller or something else (EHCI, > > UHCI, or OHCI)? > > It is directly plugged into the mainboard which only supports USB 2. > Does that answer the question? If not, how do I find out? It says in the dmesg log when you plug in the keyboard: [ 7381.444185] usb 4-1: new low-speed USB device number 3 using ohci_hcd So the answer is OHCI. > Please find the acquired logs attached. I did the following. > > 1. Keyboard unresponsive > 2. log in with SSH > 3. follow `Documentation/usb/usbmon.txt` > 4. capture the traces > > $ sudo cat /sys/kernel/debug/usb/usbmon/4u > /tmp/20120711--usbmon.out-hang-random-presses > $ sudo cat /sys/kernel/debug/usb/usbmon/4u > /tmp/20120711--usbmon.out.hang-before-unplug--asdf-return > $ sudo cat /sys/kernel/debug/usb/usbmon/4u > /tmp/20120711--usbmon.out.unplug-replug > $ sudo cat /sys/kernel/debug/usb/usbmon/4u > /tmp/20120711--usbmon.out.after-replug--asdf-return Very good. > It looks like data is received. Not only is data received; the very same data is received in both cases. Therefore the keyboard is working correctly. > So could it be an X (evdev)(?) problem? Maybe. You could test this. The next time the same thing happens, do a network login as root and run the command "chvt 2". This will change from the graphics screen to the vt2 text console. See if the keyboard works then. In theory the problem could be something really stupid. For example, typing a control-S in an xterm window (or at a text console) will suppress output to the screen until you type control-Q. 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
