Merge tag 'v5.13-rc2' into spi-5.13

Linux 5.13-rc2

1 files changed, 20 insertions, 2 deletions

diff --git a/drivers/usb/common/debug.c b/drivers/usb/common/debug.c
index ba849c7bc5c7..a76a086b9c54 100644
--- a/drivers/usb/common/debug.c
+++ b/drivers/usb/common/debug.c
@@ -207,8 +207,26 @@ static void usb_decode_set_isoch_delay(__u8 wValue, char *str, size_t size)
 	snprintf(str, size, "Set Isochronous Delay(Delay = %d ns)", wValue);
 }
 
-/*
- * usb_decode_ctrl - returns a string representation of ctrl request
+/**
+ * usb_decode_ctrl - Returns human readable representation of control request.
+ * @str: buffer to return a human-readable representation of control request.
+ *       This buffer should have about 200 bytes.
+ * @size: size of str buffer.
+ * @bRequestType: matches the USB bmRequestType field
+ * @bRequest: matches the USB bRequest field
+ * @wValue: matches the USB wValue field (CPU byte order)
+ * @wIndex: matches the USB wIndex field (CPU byte order)
+ * @wLength: matches the USB wLength field (CPU byte order)
+ *
+ * Function returns decoded, formatted and human-readable description of
+ * control request packet.
+ *
+ * The usage scenario for this is for tracepoints, so function as a return
+ * use the same value as in parameters. This approach allows to use this
+ * function in TP_printk
+ *
+ * Important: wValue, wIndex, wLength parameters before invoking this function
+ * should be processed by le16_to_cpu macro.
  */
 const char *usb_decode_ctrl(char *str, size_t size, __u8 bRequestType,
 			    __u8 bRequest, __u16 wValue, __u16 wIndex,