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

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 09-02-15 22:09, Dennis Ostermann wrote:
> 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.

This looks like the device drops of the bus when it is reset, that is not normal behavior,
there seems to be something unique to your setup causing this. Have you tried this on
multiple machines / different usb ports on your pc ? This may be something weird with the usb
controller in your machine.

>
>
>
> 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.

Which versions of libusb have you tested exactly ?

Regards,

Hans