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Subject: Re: [PATCH] ipv6: Add IN6_ADDR_GEN_MODE_STABLE_PRIVACY_SOFTMAC mode
From:   David Miller <davem@davemloft.net>
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From: Bram Bonné <brambonne@google.com>
Date: Wed, 20 May 2020 15:16:53 +0200

> Trying to change the MAC when the device is up errors with EBUSY on my
> machines, so I was under the assumption that the device needs to be
> down to change the MAC. I could very well be wrong though.

Not all drivers/devices have this limitation, the generic code allows this
just fine.