It has occurred to me that dev_set_promiscuity() and its brethren
dev_set_allmulti() may not be the best of interfaces:

- On cursory inspection of code using these function their name
implies the value of the relevant counter is set to the value passed
as parameter, not incremented by it.
- No caller I've managed to spot passes anything but -1 or 1

It seems an interface of

int dev_set_promiscuity(struct net_device *dev, bool on);

int dev_set_allmulti(struct net_device *dev, bool on);

on suggests it is an absolute, when in fact you are passing an
increment, so i don't think it is much of an improvement.

Adding #define, PROMISC_INC and PROMISC_DEC might be clearer, and
since this is not a fast path, you could consider parameter
validation. Or dev_get_promiscuity(), det_put_promiscuity().
 

would be as functional (for current users), more readable and less
error prone but I am not sure such a tiny problem (if you can call
this a problem) is worth the churn...

There was only one instance of it wrong, so it is not a very big
problem. I would say it is not worth the churn.

	 Andrew