[PATCH] USB: add usb_interrupt_msg() function for api completeness.

Really just a wrapper around usb_bulk_msg() but now it's documented
much better.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 33 insertions, 0 deletions

diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 08fb20f06f3e98..b2f608b0538df5 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -158,6 +158,37 @@ int usb_control_msg(struct usb_device *dev, unsigned int pipe, __u8 request, __u
 
 
 /**
+ * usb_interrupt_msg - Builds an interrupt urb, sends it off and waits for completion
+ * @usb_dev: pointer to the usb device to send the message to
+ * @pipe: endpoint "pipe" to send the message to
+ * @data: pointer to the data to send
+ * @len: length in bytes of the data to send
+ * @actual_length: pointer to a location to put the actual length transferred in bytes
+ * @timeout: time in msecs to wait for the message to complete before
+ *	timing out (if 0 the wait is forever)
+ * Context: !in_interrupt ()
+ *
+ * This function sends a simple interrupt message to a specified endpoint and
+ * waits for the message to complete, or timeout.
+ *
+ * If successful, it returns 0, otherwise a negative error number.  The number
+ * of actual bytes transferred will be stored in the actual_length paramater.
+ *
+ * Don't use this function from within an interrupt context, like a bottom half
+ * handler.  If you need an asynchronous message, or need to send a message
+ * from within interrupt context, use usb_submit_urb() If a thread in your
+ * driver uses this call, make sure your disconnect() method can wait for it to
+ * complete.  Since you don't have a handle on the URB used, you can't cancel
+ * the request.
+ */
+int usb_interrupt_msg(struct usb_device *usb_dev, unsigned int pipe,
+		      void *data, int len, int *actual_length, int timeout)
+{
+	return usb_bulk_msg(usb_dev, pipe, data, len, actual_length, timeout);
+}
+EXPORT_SYMBOL_GPL(usb_interrupt_msg);
+
+/**
  *	usb_bulk_msg - Builds a bulk urb, sends it off and waits for completion
  *	@usb_dev: pointer to the usb device to send the message to
  *	@pipe: endpoint "pipe" to send the message to
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 1f492c0c704743..317ec9f28bcebb 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -1008,6 +1008,8 @@ void usb_buffer_unmap_sg (struct usb_device *dev, unsigned pipe,
 extern int usb_control_msg(struct usb_device *dev, unsigned int pipe,
 	__u8 request, __u8 requesttype, __u16 value, __u16 index,
 	void *data, __u16 size, int timeout);
+extern int usb_interrupt_msg(struct usb_device *usb_dev, unsigned int pipe,
+	void *data, int len, int *actual_length, int timeout);
 extern int usb_bulk_msg(struct usb_device *usb_dev, unsigned int pipe,
 	void *data, int len, int *actual_length,
 	int timeout);