[Qemu-devel] Revert commit 5af35d7feccaa7d26b72c6c3d14116421d736b36 - "usb-host-libusb: Fix reset handling"

[Dennis Ostermann]

Hi there,

please revert commit 5af35d7feccaa7d26b72c6c3d14116421d736b36 - 
"usb-host-libusb: Fix reset handling"

This breaks usb pass through of FTDI based usb devices:

On the host:

lsusb | grep FT2232
Bus 003 Device 008: ID 0403:6010 Future Technology Devices 
International, Ltd FT2232C Dual USB-UART/FIFO IC


~/qemu-install/bin$ sudo ./qemu-system-x86_64 -monitor 
telnet:127.0.0.1:1234,server,nowait -hda /dev/sdd2 -redir tcp:20022::22 
--enable-kvm -cpu host -smp 4 -vga vmware --vnc :0 -m 8192  -usb -device 
usb-ehci,id=ehci -device 
usb-host,bus=ehci.0,vendorid=0x0403,productid=0x6010
WARNING: Image format was not specified for '/dev/sdd2' and probing 
guessed raw.
         Automatically detecting the format is dangerous for raw 
images, write operations on block 0 will be restricted.
         Specify the 'raw' format explicitly to remove the restrictions.
libusbx: error [_get_usbfs_fd] libusbx couldn't open USB device 
/dev/bus/usb/003/005: No such file or directory
libusbx: error [_get_usbfs_fd] libusbx couldn't open USB device 
/dev/bus/usb/003/006: No such file or directory
libusbx: error [_get_usbfs_fd] libusbx couldn't open USB device 
/dev/bus/usb/003/007: No such device

The device gets reset again and again and is re-enumerated every time 
and finally not passed through.



After reverting the commit:

~/qemu-patched-install/bin$ sudo ./qemu-system-x86_64 -monitor 
telnet:127.0.0.1:1234,server,nowait -hda /dev/sdd2 -redir tcp:20022::22 
--enable-kvm -cpu host -smp 4 -vga vmware --vnc :0 -m 8192  -usb -device 
usb-ehci,id=ehci -device 
usb-host,bus=ehci.0,vendorid=0x0403,productid=0x6010
WARNING: Image format was not specified for '/dev/sdd2' and probing 
guessed raw.
         Automatically detecting the format is dangerous for raw 
images, write operations on block 0 will be restricted.
         Specify the 'raw' format explicitly to remove the restrictions.


The device appears in the guest OS and can be used.

Tested with HEAD and several libusb versions. Affects at least FTDI 
FT2232H and FTDI FT232R.

Thanks and best regards,
Dennis Ostermann