On Thursday, October 10, 2013 01:59:52 PM John W. Linville wrote:

On Sat, Sep 28, 2013 at 01:16:20AM -0400, Alexey Khoroshilov wrote:

quoted

On 28.09.2013 00:17, Fabio Estevam wrote:

quoted

On Sat, Sep 28, 2013 at 12:51 AM, Alexey Khoroshilov
[off-list ref] wrote:

quoted

-       return request_firmware_nowait(THIS_MODULE, 1, CARL9170FW_NAME,
+       err = request_firmware_nowait(THIS_MODULE, 1, CARL9170FW_NAME,
                &ar->udev->dev, GFP_KERNEL, ar, carl9170_usb_firmware_step2);
+       if (err) {
+               usb_put_dev(udev);
+               usb_put_dev(udev);

You are doing the same free twice.

Yes, because it was get twice.

quoted

I guess you meant to also free: usb_put_dev(ar->udev)

udev and ar->udev are equal, so technically the patch is correct.

I agree that there is some inconsistency, but I would prefer to fix
it at usb_get_dev() side with a comment about reasons for the double
get.

What is the reason for the double get?

The idea is:
One (extra) reference protects the asynchronous firmware loader callback
from disappearing "udev".

Regards,
Chr