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Based on kernel version 4.8. Page generated on 2016-10-06 23:09 EST.

1	What:		/sys/bus/usb/devices/INTERFACE/authorized
2	Date:		August 2015
3	Description:
4			This allows to authorize (1) or deauthorize (0)
5			individual interfaces instead a whole device
6			in contrast to the device authorization.
7			If a deauthorized interface will be authorized
8			so the driver probing must be triggered manually
9			by writing INTERFACE to /sys/bus/usb/drivers_probe
10			This allows to avoid side-effects with drivers
11			that need multiple interfaces.
12			A deauthorized interface cannot be probed or claimed.
14	What:		/sys/bus/usb/devices/usbX/interface_authorized_default
15	Date:		August 2015
16	Description:
17			This is used as value that determines if interfaces
18			would be authorized by default.
19			The value can be 1 or 0. It's by default 1.
21	What:		/sys/bus/usb/device/.../authorized
22	Date:		July 2008
23	KernelVersion:	2.6.26
24	Contact:	David Vrabel <david.vrabel@csr.com>
25	Description:
26			Authorized devices are available for use by device
27			drivers, non-authorized one are not.  By default, wired
28			USB devices are authorized.
30			Certified Wireless USB devices are not authorized
31			initially and should be (by writing 1) after the
32			device has been authenticated.
34	What:		/sys/bus/usb/device/.../wusb_cdid
35	Date:		July 2008
36	KernelVersion:	2.6.27
37	Contact:	David Vrabel <david.vrabel@csr.com>
38	Description:
39			For Certified Wireless USB devices only.
41			A devices's CDID, as 16 space-separated hex octets.
43	What:		/sys/bus/usb/device/.../wusb_ck
44	Date:		July 2008
45	KernelVersion:	2.6.27
46	Contact:	David Vrabel <david.vrabel@csr.com>
47	Description:
48			For Certified Wireless USB devices only.
50			Write the device's connection key (CK) to start the
51			authentication of the device.  The CK is 16
52			space-separated hex octets.
54	What:		/sys/bus/usb/device/.../wusb_disconnect
55	Date:		July 2008
56	KernelVersion:	2.6.27
57	Contact:	David Vrabel <david.vrabel@csr.com>
58	Description:
59			For Certified Wireless USB devices only.
61			Write a 1 to force the device to disconnect
62			(equivalent to unplugging a wired USB device).
64	What:		/sys/bus/usb/drivers/.../new_id
65	Date:		October 2011
66	Contact:	linux-usb@vger.kernel.org
67	Description:
68			Writing a device ID to this file will attempt to
69			dynamically add a new device ID to a USB device driver.
70			This may allow the driver to support more hardware than
71			was included in the driver's static device ID support
72			table at compile time. The format for the device ID is:
73			idVendor idProduct bInterfaceClass RefIdVendor RefIdProduct
74			The vendor ID and device ID fields are required, the
75			rest is optional. The Ref* tuple can be used to tell the
76			driver to use the same driver_data for the new device as
77			it is used for the reference device.
78			Upon successfully adding an ID, the driver will probe
79			for the device and attempt to bind to it.  For example:
80			# echo "8086 10f5" > /sys/bus/usb/drivers/foo/new_id
82			Here add a new device (0458:7045) using driver_data from
83			an already supported device (0458:704c):
84			# echo "0458 7045 0 0458 704c" > /sys/bus/usb/drivers/foo/new_id
86			Reading from this file will list all dynamically added
87			device IDs in the same format, with one entry per
88			line. For example:
89			# cat /sys/bus/usb/drivers/foo/new_id
90			8086 10f5
91			dead beef 06
92			f00d cafe
94			The list will be truncated at PAGE_SIZE bytes due to
95			sysfs restrictions.
97	What:		/sys/bus/usb-serial/drivers/.../new_id
98	Date:		October 2011
99	Contact:	linux-usb@vger.kernel.org
100	Description:
101			For serial USB drivers, this attribute appears under the
102			extra bus folder "usb-serial" in sysfs; apart from that
103			difference, all descriptions from the entry
104			"/sys/bus/usb/drivers/.../new_id" apply.
106	What:		/sys/bus/usb/drivers/.../remove_id
107	Date:		November 2009
108	Contact:	CHENG Renquan <rqcheng@smu.edu.sg>
109	Description:
110			Writing a device ID to this file will remove an ID
111			that was dynamically added via the new_id sysfs entry.
112			The format for the device ID is:
113			idVendor idProduct.	After successfully
114			removing an ID, the driver will no longer support the
115			device.  This is useful to ensure auto probing won't
116			match the driver to the device.  For example:
117			# echo "046d c315" > /sys/bus/usb/drivers/foo/remove_id
119			Reading from this file will list the dynamically added
120			device IDs, exactly like reading from the entry
121			"/sys/bus/usb/drivers/.../new_id"
123	What:		/sys/bus/usb/devices/.../power/usb2_hardware_lpm
124	Date:		September 2011
125	Contact:	Andiry Xu <andiry.xu@amd.com>
126	Description:
127			If CONFIG_PM is set and a USB 2.0 lpm-capable device is plugged
128			in to a xHCI host which support link PM, it will perform a LPM
129			test; if the test is passed and host supports USB2 hardware LPM
130			(xHCI 1.0 feature), USB2 hardware LPM will be enabled for the
131			device and the USB device directory will contain a file named
132			power/usb2_hardware_lpm.  The file holds a string value (enable
133			or disable) indicating whether or not USB2 hardware LPM is
134			enabled for the device. Developer can write y/Y/1 or n/N/0 to
135			the file to enable/disable the feature.
137	What:		/sys/bus/usb/devices/.../power/usb3_hardware_lpm_u1
138			/sys/bus/usb/devices/.../power/usb3_hardware_lpm_u2
139	Date:		November 2015
140	Contact:	Kevin Strasser <kevin.strasser@linux.intel.com>
141			Lu Baolu <baolu.lu@linux.intel.com>
142	Description:
143			If CONFIG_PM is set and a USB 3.0 lpm-capable device is plugged
144			in to a xHCI host which supports link PM, it will check if U1
145			and U2 exit latencies have been set in the BOS descriptor; if
146			the check is passed and the host supports USB3 hardware LPM,
147			USB3 hardware LPM will be enabled for the device and the USB
148			device directory will contain two files named
149			power/usb3_hardware_lpm_u1 and power/usb3_hardware_lpm_u2. These
150			files hold a string value (enable or disable) indicating whether
151			or not USB3 hardware LPM U1 or U2 is enabled for the device.
153	What:		/sys/bus/usb/devices/.../removable
154	Date:		February 2012
155	Contact:	Matthew Garrett <mjg@redhat.com>
156	Description:
157			Some information about whether a given USB device is
158			physically fixed to the platform can be inferred from a
159			combination of hub descriptor bits and platform-specific data
160			such as ACPI. This file will read either "removable" or
161			"fixed" if the information is available, and "unknown"
162			otherwise.
164	What:		/sys/bus/usb/devices/.../ltm_capable
165	Date:		July 2012
166	Contact:	Sarah Sharp <sarah.a.sharp@linux.intel.com>
167	Description:
168			USB 3.0 devices may optionally support Latency Tolerance
169			Messaging (LTM).  They indicate their support by setting a bit
170			in the bmAttributes field of their SuperSpeed BOS descriptors.
171			If that bit is set for the device, ltm_capable will read "yes".
172			If the device doesn't support LTM, the file will read "no".
173			The file will be present for all speeds of USB devices, and will
174			always read "no" for USB 1.1 and USB 2.0 devices.
176	What:		/sys/bus/usb/devices/.../(hub interface)/portX
177	Date:		August 2012
178	Contact:	Lan Tianyu <tianyu.lan@intel.com>
179	Description:
180			The /sys/bus/usb/devices/.../(hub interface)/portX
181			is usb port device's sysfs directory.
183	What:		/sys/bus/usb/devices/.../(hub interface)/portX/connect_type
184	Date:		January 2013
185	Contact:	Lan Tianyu <tianyu.lan@intel.com>
186	Description:
187			Some platforms provide usb port connect types through ACPI.
188			This attribute is to expose these information to user space.
189			The file will read "hotplug", "wired" and "not used" if the
190			information is available, and "unknown" otherwise.
192	What:		/sys/bus/usb/devices/.../(hub interface)/portX/usb3_lpm_permit
193	Date:		November 2015
194	Contact:	Lu Baolu <baolu.lu@linux.intel.com>
195	Description:
196			Some USB3.0 devices are not friendly to USB3 LPM.  usb3_lpm_permit
197			attribute allows enabling/disabling usb3 lpm of a port. It takes
198			effect both before and after a usb device is enumerated. Supported
199			values are "0" if both u1 and u2 are NOT permitted, "u1" if only u1
200			is permitted, "u2" if only u2 is permitted, "u1_u2" if both u1 and
201			u2 are permitted.
203	What:		/sys/bus/usb/devices/.../power/usb2_lpm_l1_timeout
204	Date:		May 2013
205	Contact:	Mathias Nyman <mathias.nyman@linux.intel.com>
206	Description:
207			USB 2.0 devices may support hardware link power management (LPM)
208			L1 sleep state. The usb2_lpm_l1_timeout attribute allows
209			tuning the timeout for L1 inactivity timer (LPM timer), e.g.
210			needed inactivity time before host requests the device to go to L1 sleep.
211			Useful for power management tuning.
212			Supported values are 0 - 65535 microseconds.
214	What:		/sys/bus/usb/devices/.../power/usb2_lpm_besl
215	Date:		May 2013
216	Contact:	Mathias Nyman <mathias.nyman@linux.intel.com>
217	Description:
218			USB 2.0 devices that support hardware link power management (LPM)
219			L1 sleep state now use a best effort service latency value (BESL) to
220			indicate the best effort to resumption of service to the device after the
221			initiation of the resume event.
222			If the device does not have a preferred besl value then the host can select
223			one instead. This usb2_lpm_besl attribute allows to tune the host selected besl
224			value in order to tune power saving and service latency.
226			Supported values are 0 - 15.
227			More information on how besl values map to microseconds can be found in
228			USB 2.0 ECN Errata for Link Power Management, section 4.10)
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