Shuah, this driver is getting more and more cryptic and buggy. Please explain the strategy for serialization before you write patches. > - Fix attach_store() to check usbip_event_happened() before > waking up threads. No, this helps nothing. > diff --git a/drivers/usb/usbip/vhci_sysfs.c b/drivers/usb/usbip/vhci_sysfs.c > index c4b4256e5dad3..f0a770adebd97 100644 > --- a/drivers/usb/usbip/vhci_sysfs.c > +++ b/drivers/usb/usbip/vhci_sysfs.c > @@ -418,6 +418,15 @@ static ssize_t attach_store(struct device *dev, struct device_attribute *attr, > spin_unlock_irqrestore(&vhci->lock, flags); > /* end the lock */ > > + if (usbip_event_happened(&vdev->ud)) { > + /* > + * something went wrong - event handler shutting > + * the connection and doing reset - bail out > + */ > + dev_err(dev, "Event happended - handler is active\n"); > + return -EAGAIN; > + } > + detach_store() can queue shutdown event as soon as reaching "/* end the lock */" line but attach_store() might be preempted immediately after verifying that usbip_event_happened() was false (i.e. at this location) in order to wait for shutdown event posted by detach_store() to be processed. > wake_up_process(vdev->ud.tcp_rx); > wake_up_process(vdev->ud.tcp_tx); >