media: stkwebcam: fix runtime PM after driver unbind

BugLink: https://bugs.launchpad.net/bugs/1850541
commit 30045f2174aab7fb4db7a9cf902d0aa6c75856a7 upstream.

Since commit c2b71462d294 ("USB: core: Fix bug caused by duplicate
interface PM usage counter") USB drivers must always balance their
runtime PM gets and puts, including when the driver has already been
unbound from the interface.

Leaving the interface with a positive PM usage counter would prevent a
later bound driver from suspending the device.

Note that runtime PM has never actually been enabled for this driver
since the support_autosuspend flag in its usb_driver struct is not set.

Fixes: c2b71462d294 ("USB: core: Fix bug caused by duplicate interface PM usage counter")
Cc: stable <stable@vger.kernel.org>
Acked-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191001084908.2003-5-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/drivers/media/usb/stkwebcam/stk-webcam.c b/drivers/media/usb/stkwebcam/stk-webcam.c
index c0bba773db25b0032bfb3f422117c6d08de5e382..a7da1356a36ef57ec975b21b50a5b19588cd5c86 100644 (file)
--- a/drivers/media/usb/stkwebcam/stk-webcam.c
+++ b/drivers/media/usb/stkwebcam/stk-webcam.c
@@ -640,8 +640,7 @@ static int v4l_stk_release(struct file *fp)
                dev->owner = NULL;
        }
 
-       if (is_present(dev))
-               usb_autopm_put_interface(dev->interface);
+       usb_autopm_put_interface(dev->interface);
        mutex_unlock(&dev->lock);
        return v4l2_fh_release(fp);
 }