From ec91aff7630df1e1864d95f5efd25c212d484837 Mon Sep 17 00:00:00 2001 From: Andrzej Pietrasiewicz Date: Tue, 16 Dec 2014 14:56:31 +0100 Subject: [PATCH] Documentation: usb: LOOPBACK function testing Summary of how to test LOOPBACK function of USB gadget. Signed-off-by: Andrzej Pietrasiewicz Signed-off-by: Felipe Balbi --- Documentation/usb/gadget-testing.txt | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/Documentation/usb/gadget-testing.txt b/Documentation/usb/gadget-testing.txt index f117e5c84a1e..b13491d1e352 100644 --- a/Documentation/usb/gadget-testing.txt +++ b/Documentation/usb/gadget-testing.txt @@ -7,6 +7,7 @@ provided by gadgets. 4. EEM function 5. FFS function 6. HID function +7. LOOPBACK function 1. ACM function @@ -205,3 +206,25 @@ $ ./hid_gadget_test /dev/hidg0 keyboard Host: - observe the keystrokes from the gadget + +7. LOOPBACK function +==================== + +The function is provided by usb_f_ss_lb.ko module. + +Function-specific configfs interface +------------------------------------ + +The function name to use when creating the function directory is "Loopback". +The LOOPBACK function provides these attributes in its function directory: + + qlen - depth of loopback queue + bulk_buflen - buffer length + +Testing the LOOPBACK function +----------------------------- + +device: run the gadget +host: test-usb + +http://www.linux-usb.org/usbtest/testusb.c