On Mon, Mar 11, 2013 at 11:32 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > Of course you have to lock the device before changing its driver. What > would happen if two different threads tried to change a device's driver > at the same time? Yes, claim/release interface need device lock, but the patch doesn't touch claim/release command handling. > > usbdev_do_ioctl() needs to acquire the device lock in order to prevent > races with driver_disconnect() and usbdev_remove(). Looks the patch basically converts the allocation inside URB submit path, and actually I mean why we need to hold device lock in submitting URB path? Device lock isn't required before submitting URBs in kernel driver. Thanks, -- Ming Lei -- 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
