usbtmc: Add, clarify and fix comments
Add information regarding lifespan of kref protection:
Clarify comment on kref_get for interrupt in urb in usbtmc_probe()
Add comment on kref_get in usbtmc_open()
Fix endpoint reference in documentation for send_request_dev_dep_msg_in()
Signed-off-by: Dave Penkler <dpenkler@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index a6c1fae..f03692e 100644
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -157,6 +157,7 @@
}
data = usb_get_intfdata(intf);
+ /* Protect reference to data from file structure until release */
kref_get(&data->kref);
/* Store pointer in file structure's private data field */
@@ -531,7 +532,7 @@
}
/*
- * Sends a REQUEST_DEV_DEP_MSG_IN message on the Bulk-IN endpoint.
+ * Sends a REQUEST_DEV_DEP_MSG_IN message on the Bulk-OUT endpoint.
* @transfer_size: number of bytes to request from the device.
*
* See the USBTMC specification, Table 4.
@@ -1471,7 +1472,7 @@
if (!data->iin_urb)
goto error_register;
- /* will reference data in int urb */
+ /* Protect interrupt in endpoint data until iin_urb is freed */
kref_get(&data->kref);
/* allocate buffer for interrupt in */