Hi All, I'm currently working on usb-redirection over the network, iow tunneling usb transfers over a network connection. The most significant use case for this is taking a usb device attached to some machine "a" which acts as a client / viewer to a virtual machine "v" hosted on another machine "b", and make the usb device show up inside the virtual machine as if it were attached directly to the virtual machine "v". Under Linux I'm using libusb/usbfs to access the real usb device on the client machine (currently using kernel 2.6.35.6). When ever the guest os does a usb reset, and I forward this to the real device, the usbfs driver gets detached from all the interfaces, and after the reset the normal linux drivers attach to the device again. So what I currently do / what currently happens is: 1: -start the usb-host process which takes over the real usb device and "connects" it to the guest (over a tcp socket) -the guest os sees a a new device -the guest os resets it 2: -the linux kernel detaches all the usbfs driver from all interfaces -the linux kernel does the reset -the linux kernel attaches the regular linux driver to all interfaces -the regular driver likely does some stuff with the device 3: -My code needs to redo, for all interfaces: -the linux driver gets detached -the interface gets claimed After reading the kernel code I've found out that it would be a good idea to claim the hub port, this should stop the native linux drivers from re-attaching to the device after the reset. Changing 2 and 3 into: 2: -the linux kernel detaches all the usbfs driver from all interfaces -the linux kernel does the reset 3: -My code needs to redo, for all interfaces: -the interface gets claimed Which is much better. But I was wondering if it wouldn't be even better to add a .pre_reset and .post_reset code to the usbfs driver, so that 2 changes into just: 2: -the linux kernel does the reset IOW the usbfs driver does not get detached for a reset. So what do others think. Would it be a good idea to change things this way, or is the usbfs driver detaching intended / expected behavior? Thanks & Regards, Hans -- 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
