kernel_optimize_test/Documentation/ABI/testing/sysfs-bus-usb-lvstest
Jack Pham f624ec70b4 usb: misc: lvstest: add entry to place port in compliance mode
Add support for the SuperSpeed Link Layer test case TD.7.34
which requires the operator to place the port into compliance
mode, and to subsequently bring it out via reset. Historically
according to the (now deprecated) USB 3.0 specification a
SuperSpeed host downstream port would automatically transition
to Compliance mode from the Polling state if LFPS polling times
out. However the language in USB 3.1 as well as xHCI 1.1 states
it may be required to explicitly enable this transition. For
such hosts this is done by sending a SET_FEATURE(PORT_LINK_STATE)
with the state set to Compliance to the root hub port.

Similar to the other supported commands, to do this via sysfs:

     echo  > /sys/bus/usb/devices/2-0\:1.0/enable_compliance

According to xHCI 1.1 section 4.19.1.2.4.1, this enables the
transition to compliance mode upon LFPS timeout. Note that this
can only be issued when the port is in disconnected state. And
in order to disable this behavior on subsequent transitions, a
warm reset should be issued. So add another entry to do that:

     echo  > /sys/bus/usb/devices/2-0\:1.0/warm_reset

In general these attributes can also be useful for other USB
SuperSpeed compliance tests such as electrical and eye diagram
testing which require CPn patterns to be transmitted.

Signed-off-by: Jack Pham <jackp@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28 11:43:39 +02:00

61 lines
2.2 KiB
Plaintext

Link Layer Validation Device is a standard device for testing of Super
Speed Link Layer tests. These nodes are available in sysfs only when lvs
driver is bound with root hub device.
What: /sys/bus/usb/devices/.../get_dev_desc
Date: March 2014
Contact: Pratyush Anand <pratyush.anand@gmail.com>
Description:
Write to this node to issue "Get Device Descriptor"
for Link Layer Validation device. It is needed for TD.7.06.
What: /sys/bus/usb/devices/.../u1_timeout
Date: March 2014
Contact: Pratyush Anand <pratyush.anand@gmail.com>
Description:
Set "U1 timeout" for the downstream port where Link Layer
Validation device is connected. Timeout value must be between 0
and 127. It is needed for TD.7.18, TD.7.19, TD.7.20 and TD.7.21.
What: /sys/bus/usb/devices/.../u2_timeout
Date: March 2014
Contact: Pratyush Anand <pratyush.anand@gmail.com>
Description:
Set "U2 timeout" for the downstream port where Link Layer
Validation device is connected. Timeout value must be between 0
and 127. It is needed for TD.7.18, TD.7.19, TD.7.20 and TD.7.21.
What: /sys/bus/usb/devices/.../hot_reset
Date: March 2014
Contact: Pratyush Anand <pratyush.anand@gmail.com>
Description:
Write to this node to issue "Reset" for Link Layer Validation
device. It is needed for TD.7.29, TD.7.31, TD.7.34 and TD.7.35.
What: /sys/bus/usb/devices/.../u3_entry
Date: March 2014
Contact: Pratyush Anand <pratyush.anand@gmail.com>
Description:
Write to this node to issue "U3 entry" for Link Layer
Validation device. It is needed for TD.7.35 and TD.7.36.
What: /sys/bus/usb/devices/.../u3_exit
Date: March 2014
Contact: Pratyush Anand <pratyush.anand@gmail.com>
Description:
Write to this node to issue "U3 exit" for Link Layer
Validation device. It is needed for TD.7.36.
What: /sys/bus/usb/devices/.../enable_compliance
Date: July 2017
Description:
Write to this node to set the port to compliance mode to test
with Link Layer Validation device. It is needed for TD.7.34.
What: /sys/bus/usb/devices/.../warm_reset
Date: July 2017
Description:
Write to this node to issue "Warm Reset" for Link Layer Validation
device. It may be needed to properly reset an xHCI 1.1 host port if
compliance mode needed to be explicitly enabled.