2021-07-29 00:47:10

by Salah Triki

Subject: [RESEND v2] hid-elo: update the reference count of the usb device structure

Use usb_get_dev() to increment the reference count of the usb device
structure in order to avoid releasing the structure while it is still in
use. And use usb_put_dev() to decrement the reference count and thus,
when it will be equal to 0 the structure will be released.

Signed-off-by: Salah Triki <[email protected]>
---
Change since v1:
Modification of the description

drivers/hid/hid-elo.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-elo.c b/drivers/hid/hid-elo.c
index 0d22713a3874..383dfda8c12f 100644
--- a/drivers/hid/hid-elo.c
+++ b/drivers/hid/hid-elo.c
@@ -228,13 +228,15 @@ static int elo_probe(struct hid_device *hdev, const struct hid_device_id *id)
{
struct elo_priv *priv;
int ret;
+ struct usb_device *udev;

priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;

INIT_DELAYED_WORK(&priv->work, elo_work);
- priv->usbdev = interface_to_usbdev(to_usb_interface(hdev->dev.parent));
+ udev = interface_to_usbdev(to_usb_interface(hdev->dev.parent));
+ priv->usbdev = usb_get_dev(udev);

hid_set_drvdata(hdev, priv);

@@ -265,6 +267,8 @@ static void elo_remove(struct hid_device *hdev)
{
struct elo_priv *priv = hid_get_drvdata(hdev);

+ usb_put_dev(priv->usbdev);
+
hid_hw_stop(hdev);
cancel_delayed_work_sync(&priv->work);
kfree(priv);
--
2.25.1

2021-08-20 12:24:21

by Jiri Kosina

Subject: Re: [RESEND v2] hid-elo: update the reference count of the usb device structure

On Thu, 29 Jul 2021, Salah Triki wrote:

> Use usb_get_dev() to increment the reference count of the usb device
> structure in order to avoid releasing the structure while it is still in
> use. And use usb_put_dev() to decrement the reference count and thus,
> when it will be equal to 0 the structure will be released.

Applied, thanks for spotting this.

--
Jiri Kosina
SUSE Labs