usb 插入拔出 对应数字 状态
usb usb2: usb_set_device_state 7->8
enum usb_device_state {
/* NOTATTACHED isn't in the USB spec, and this state acts
* the same as ATTACHED ... but it's clearer this way.
*/
USB_STATE_NOTATTACHED = 0,
/* chapter 9 and authentication (wireless) device states */
USB_STATE_ATTACHED,
USB_STATE_POWERED, /* wired */
USB_STATE_RECONNECTING, /* auth */
USB_STATE_UNAUTHENTICATED, /* auth */
USB_STATE_DEFAULT, /* limited function */
USB_STATE_ADDRESS,
USB_STATE_CONFIGURED, /* most functions */
USB_STATE_SUSPENDED
/* NOTE: there are actually four different SUSPENDED
* states, returning to POWERED, DEFAULT, ADDRESS, or
* CONFIGURED respectively when SOF tokens flow again.
* At this level there's no difference between L1 and L2
* suspend states. (L2 being original USB 1.1 suspend.)
*/
};