USB: unconfigure devices which have config 0
Some USB devices do have a configuration 0, in contravention of the USB spec. Normally 0 is supposed to indicate that a device is unconfigured. While we can't change what the device is doing, we can change usbcore. This patch (as852) allows usb_set_configuration() to accept a config value of -1 as indicating that the device should be unconfigured. The request actually sent to the device will still contain 0 as the value. But even if the device does have a configuration 0, dev->actconfig will be set to NULL and dev->state will be set to USB_STATE_ADDRESS. Without some sort of special-case handling like this, there is no way to unconfigure these non-compliant devices. Signed-off-by: NAlan Stern <stern@rowland.harvard.edu> Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Showing
想要评论请 注册 或 登录