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>
This commit is contained in:
Dave Penkler 2016-09-28 20:06:01 +02:00 committed by Greg Kroah-Hartman
parent 864e2fe935
commit 88aecde40b

View File

@ -157,6 +157,7 @@ static int usbtmc_open(struct inode *inode, struct file *filp)
}
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 @@ static int usbtmc488_ioctl_simple(struct usbtmc_device_data *data,
}
/*
* 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 @@ static int usbtmc_probe(struct usb_interface *intf,
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 */