rx_lanes and tx_lanes sysfs entries show the number of lanes in use by a device. USB 3.2 adds support for Dual-lane (symmetrical), using 2 rx lanes and 2 tx lanes for normal non Inter-Chip SSIC devices. USB 3.1 and older are all single lane.
SSIC devices can have up to 4 lanes per direction in use, with different number of rx and tx lanes. Signed-off-by: Mathias Nyman <[email protected]> --- Documentation/ABI/testing/sysfs-bus-usb | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb index c702c78..c6e9b30 100644 --- a/Documentation/ABI/testing/sysfs-bus-usb +++ b/Documentation/ABI/testing/sysfs-bus-usb @@ -236,3 +236,21 @@ Description: Supported values are 0 - 15. More information on how besl values map to microseconds can be found in USB 2.0 ECN Errata for Link Power Management, section 4.10) + +What: /sys/bus/usb/devices/.../rx_lanes +Date: March 2018 +Contact: Mathias Nyman <[email protected]> +Description: + Number of rx lanes the device is using. + USB 3.2 adds Dual-lane support, 2 rx and 2 tx lanes over Type-C. + Inter-Chip SSIC devices support asymmetric lanes up to 4 lanes per + direction. Devices before USB 3.2 are single lane (rx_lanes = 1) + +What: /sys/bus/usb/devices/.../tx_lanes +Date: March 2018 +Contact: Mathias Nyman <[email protected]> +Description: + Number of tx lanes the device is using. + USB 3.2 adds Dual-lane support, 2 rx and 2 tx -lanes over Type-C. + Inter-Chip SSIC devices support asymmetric lanes up to 4 lanes per + direction. Devices before USB 3.2 are single lane (tx_lanes = 1) -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
