Triaging old bug tickets ... Can you still reproduce this problem with the latest version of QEMU and the latest version of libusb? If so, could you please also provide the command line options that you used to start QEMU?
** Changed in: qemu Status: New => Incomplete -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/906221 Title: USBDEVFS_CLEAR_HALT stall with USB-CDROM qemu-1.0 Status in QEMU: Incomplete Bug description: When connecting a USB DVD/CDROM drive to the linux host, it works fine and I can mount the inserted DVD properly and work with it. After unmounting the DVD and routing the USB drive to the linux guest (same kernel version), both host and guest become unresponsive and on the QEMU console I get the QEMU console flodded with the message: USBDEVFS_CLEAR_HALT: Connection timed out again and again, approx. each 10-20 seconds. When I unplug the device from the host, the message USBDEVFS_CLEAR_HALT: No such device comes up in one block at least 100 times (my scrollback history of the display is limited, so I cannot say how often it actually appreared) On the guest side linux, I see the following dmesg after having it routed from the host to the guest: [ 160.292231] usb 1-2.1: new full speed USB device using uhci_hcd and address 5 [ 160.475762] usb 1-2.1: configuration #1 chosen from 1 choice [ 160.478553] scsi3 : SCSI emulation for USB Mass Storage devices [ 160.479689] usb-storage: device found at 5 [ 160.480121] usb-storage: waiting for device to settle before scanning [ 165.494016] scsi 3:0:0:0: CD-ROM slimtype eTDU108 1 SL03 PQ: 0 ANSI: 0 then, the guest stalls and on the host side the USBDEVFS_CLEAR_HALT appears until I unplug the hardware from the host - pay also attention on the stalled dmesg timestamp! The "real" timegap between the last line above and the first line below is more than 20 seconds! [ 165.645735] usb 1-2.1: USB disconnect, address 5 [ 165.663770] sr0: scsi3-mmc drive: 24x/24x cd/rw xa/form2 cdda pop-up [ 165.664416] sr 3:0:0:0: Attached scsi CD-ROM sr0 [ 165.664623] sr 3:0:0:0: Attached scsi generic sg1 type 5 [ 165.665565] usb-storage: device scan complete The drive used is a self-powered LITEON External Slim DVD-ROM Drive (Model number eTDU108-02 1) The power is not a problem, because the drive works fine on the host directly. Best regards, Erik To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/906221/+subscriptions