On Thu, Sep 04, 2025 at 09:52:03AM +0200, Oliver Neukum wrote:

On 9/4/25 09:26, Xu Yang wrote:

quoted

quoted

quoted

   	/* allow minidriver to stop correctly (wireless devices to turn off
   	 * radio etc) */
-	if (info->stop) {
+	if (info->stop && !dev->suspend_count) {

... for !dev->suspend_count to be false

The suspend_count won't go to 0 because there is no chance to call
usbnet_resume() if the USB device is physically disconnected from the
USB port during system suspend.

Sorry for the delay.

While you are correct that a physical disconnect
will make the PM call fail, you cannot assume that
a physical disconnect is the only reason disconnect()
would be called.
It would also be called if

- the module is unloaded
- usbfs is used to disconnect the driver from the device

I understand your concern, however, it seems that only disconnect during
the PM operations then the suspend_count will be non-zero.

Hence it seems to me that using suspend_count is false.
You need to use the return of the PM operation.

And a non-zero suspend_count itself is also a PM operation result, isn't it?

Besides, the another way we can determine whether the device has been
unattached, like following:

@@ -839,7 +839,7 @@ int usbnet_stop (struct net_device *net)
        pm = usb_autopm_get_interface(dev->intf);
        /* allow minidriver to stop correctly (wireless devices to turn off
         * radio etc) */
-       if (info->stop) {
+       if (info->stop && dev->udev->state != USB_STATE_NOTATTACHED) {
                retval = info->stop(dev);
                if (retval < 0)
                        netif_info(dev, ifdown, dev->net,

So if it's already in NOTATTACHED state, no needs to stop the device too.

Do you prefer this way?

Thanks,
Xu Yang

	Regards
		Oliver