On Thu, Sep 04, 2025 at 09:52:03AM +0200, Oliver Neukum wrote:
>
>
> On 9/4/25 09:26, Xu Yang wrote:
> > > > /* 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
>
>
