[PATCH 2/2] gpib: ni_usb: drop redundant device reference

Johan Hovold posted 2 patches 1 month ago
[PATCH 2/2] gpib: ni_usb: drop redundant device reference
Posted by Johan Hovold 1 month ago
Driver core holds a reference to the USB interface and its parent USB
device while the interface is bound to a driver and there is no need to
take additional references unless the structures are needed after
disconnect.

Drop the redundant device reference to reduce cargo culting, make it
easier to spot drivers where an extra reference is needed, and reduce
the risk of memory leaks when drivers fail to release it.

Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/gpib/ni_usb/ni_usb_gpib.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/gpib/ni_usb/ni_usb_gpib.c b/drivers/gpib/ni_usb/ni_usb_gpib.c
index a24cd6521362..0bbc13ecebf9 100644
--- a/drivers/gpib/ni_usb/ni_usb_gpib.c
+++ b/drivers/gpib/ni_usb/ni_usb_gpib.c
@@ -2431,7 +2431,6 @@ static int ni_usb_driver_probe(struct usb_interface *interface,	const struct usb
 	static const int path_length = 1024;
 
 	mutex_lock(&ni_usb_hotplug_lock);
-	usb_get_dev(usb_dev);
 	for (i = 0; i < MAX_NUM_NI_USB_INTERFACES; i++) {
 		if (!ni_usb_driver_interfaces[i]) {
 			ni_usb_driver_interfaces[i] = interface;
@@ -2440,14 +2439,12 @@ static int ni_usb_driver_probe(struct usb_interface *interface,	const struct usb
 		}
 	}
 	if (i == MAX_NUM_NI_USB_INTERFACES) {
-		usb_put_dev(usb_dev);
 		mutex_unlock(&ni_usb_hotplug_lock);
 		dev_err(&usb_dev->dev, "ni_usb_driver_interfaces[] full\n");
 		return -1;
 	}
 	path = kmalloc(path_length, GFP_KERNEL);
 	if (!path) {
-		usb_put_dev(usb_dev);
 		mutex_unlock(&ni_usb_hotplug_lock);
 		return -ENOMEM;
 	}
@@ -2488,7 +2485,6 @@ static void ni_usb_driver_disconnect(struct usb_interface *interface)
 	}
 	if (i == MAX_NUM_NI_USB_INTERFACES)
 		dev_err(&usb_dev->dev, "unable to find interface  bug?\n");
-	usb_put_dev(usb_dev);
 	mutex_unlock(&ni_usb_hotplug_lock);
 }
 
-- 
2.52.0