[PATCH] input: pxrc - do not store USB device in private struct

From: Marcus Folkesson
Date: Mon Jul 16 2018 - 10:41:05 EST


The USB device is only needed during setup, so put it back after
initialization and do not store it in our private struct.

Also, the USB device is a parent of USB interface so our driver
model rules ensure that USB device should not disappear while
interface device is still there.
So not keep a refcount on the device is safe.

Reported-by: Alexey Khoroshilov <khoroshilov@xxxxxxxxx>
Signed-off-by: Marcus Folkesson <marcus.folkesson@xxxxxxxxx>
---
drivers/input/joystick/pxrc.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/input/joystick/pxrc.c b/drivers/input/joystick/pxrc.c
index 07a0dbd3ced2..46a7acb747bf 100644
--- a/drivers/input/joystick/pxrc.c
+++ b/drivers/input/joystick/pxrc.c
@@ -27,7 +27,6 @@ MODULE_DEVICE_TABLE(usb, pxrc_table);

struct pxrc {
struct input_dev *input;
- struct usb_device *udev;
struct usb_interface *intf;
struct urb *urb;
struct mutex pm_mutex;
@@ -120,7 +119,7 @@ static void pxrc_close(struct input_dev *input)
mutex_unlock(&pxrc->pm_mutex);
}

-static int pxrc_usb_init(struct pxrc *pxrc)
+static int pxrc_usb_init(struct pxrc *pxrc, struct usb_device *udev)
{
struct usb_endpoint_descriptor *epirq;
unsigned int pipe;
@@ -145,7 +144,7 @@ static int pxrc_usb_init(struct pxrc *pxrc)
}

usb_set_intfdata(pxrc->intf, pxrc);
- usb_make_path(pxrc->udev, pxrc->phys, sizeof(pxrc->phys));
+ usb_make_path(udev, pxrc->phys, sizeof(pxrc->phys));
strlcat(pxrc->phys, "/input0", sizeof(pxrc->phys));

pxrc->urb = usb_alloc_urb(0, GFP_KERNEL);
@@ -154,8 +153,8 @@ static int pxrc_usb_init(struct pxrc *pxrc)
goto error;
}

- pipe = usb_rcvintpipe(pxrc->udev, pxrc->epaddr),
- usb_fill_int_urb(pxrc->urb, pxrc->udev, pipe, pxrc->data, pxrc->bsize,
+ pipe = usb_rcvintpipe(udev, pxrc->epaddr),
+ usb_fill_int_urb(pxrc->urb, udev, pipe, pxrc->data, pxrc->bsize,
pxrc_usb_irq, pxrc, 1);

error:
@@ -164,7 +163,7 @@ static int pxrc_usb_init(struct pxrc *pxrc)

}

-static int pxrc_input_init(struct pxrc *pxrc)
+static int pxrc_input_init(struct pxrc *pxrc, struct usb_device *udev)
{
pxrc->input = devm_input_allocate_device(&pxrc->intf->dev);
if (pxrc->input == NULL) {
@@ -174,7 +173,7 @@ static int pxrc_input_init(struct pxrc *pxrc)

pxrc->input->name = "PXRC Flight Controller Adapter";
pxrc->input->phys = pxrc->phys;
- usb_to_input_id(pxrc->udev, &pxrc->input->id);
+ usb_to_input_id(udev, &pxrc->input->id);

pxrc->input->open = pxrc_open;
pxrc->input->close = pxrc_close;
@@ -197,6 +196,7 @@ static int pxrc_probe(struct usb_interface *intf,
const struct usb_device_id *id)
{
struct pxrc *pxrc;
+ struct usb_device *udev;
int retval;

pxrc = devm_kzalloc(&intf->dev, sizeof(*pxrc), GFP_KERNEL);
@@ -204,23 +204,25 @@ static int pxrc_probe(struct usb_interface *intf,
return -ENOMEM;

mutex_init(&pxrc->pm_mutex);
- pxrc->udev = usb_get_dev(interface_to_usbdev(intf));
+ udev = usb_get_dev(interface_to_usbdev(intf));
pxrc->intf = intf;

- retval = pxrc_usb_init(pxrc);
+ retval = pxrc_usb_init(pxrc, udev);
if (retval)
goto error;

- retval = pxrc_input_init(pxrc);
+ retval = pxrc_input_init(pxrc, udev);
if (retval)
goto err_free_urb;

+ usb_put_dev(udev);
return 0;

err_free_urb:
usb_free_urb(pxrc->urb);

error:
+ usb_put_dev(udev);
return retval;
}

--
2.18.0