Re: [PATCH] allow setting wiphy.perm_addr after driver probe

Hi Daniel,

quoted

The initial wlan0 can be removed as every other netdev attached to the
wiphy. It can also be as easily re-created.

Since the wiphy does not have a valid MAC address, my proposal here
would be to just not create the wlan0 in the first place. This means
that the wiphy can be still discovered via nl80211.

I repeat, currently wlan0 is *not* created.

what kind of hardware are you actually using here?

quoted

It also means that the wlan0 netdev needs to be created by userspace
now. And a valid NL80211_ATTR_MAC be provided. Similar to what is
already done for P2P devices at the moment. That should just solve the
problem.

The creation of wlan0 already comes from userspace, but the PHY has its
own MAC.

quoted

We really do not want to announce a netdev when registering the wiphy
device and then having to mess with its MAC address via sysfs somehow.
This all needs to be properly reflected over RTNL.

Again, no netdev is announced. There just isn't a way to set the MAC of
the wiphy device itself.

How about this: What if the driver were to leave the MAC at all zeros
initially, and sysfs could set that if and only if it's all zeros at the
time?

Internally it might do that, but I do not see it exposing the NL80211_ATTR_MAC when you get the attributes for wiphy.

So I am still saying that when you do NL80211_CMD_NEW_INTERFACE allow providing NL80211_ATTR_MAC to set the MAC address to be used. It might be useful that the wiphy exposes an attribute saying that it does not have a default MAC address, but that should be it. I do not like these magic 00:00:00:00:00:00 games. As I mentioned earlier, in Bluetooth we just deal with allowing the driver to set a flag that it does not have a valid address. And then the core takes care of dealing with it.

Regards

Marcel