/sys/module/usbcore/parameters/

結構いろいろ指定できるのね。

usbcore.autosuspend=
		[USB] The autosuspend time delay (in seconds) used
		for newly-detected USB devices (default 2).  This
		is the time required before an idle device will be
		autosuspended.  Devices for which the delay is set
		to a negative value won't be autosuspended at all.

usbcore.usbfs_snoop=
		[USB] Set to log all usbfs traffic (default 0 = off).

usbcore.blinkenlights=
		[USB] Set to cycle leds on hubs (default 0 = off).

usbcore.old_scheme_first=
		[USB] Start with the old device initialization
		scheme (default 0 = off).

usbcore.use_both_schemes=
		[USB] Try the other device initialization scheme
		if the first one fails (default 1 = enabled).
	
usbcore.initial_descriptor_timeout=
		[USB] Specifies timeout for the initial 64-byte
                USB_REQ_GET_DESCRIPTOR request in milliseconds
		(default 5000 = 5.0 seconds).