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Message-ID: <f5986ccd8ecdcc08d5c3e0d65f8bddef8b0af021.camel@sipsolutions.net>
Subject: Re: [PATCH 1/2] nl80211: Add NL80211_EXT_FEATURE_LIVE_IFTYPE_CHANGE
From:   Johannes Berg <johannes@sipsolutions.net>
To:     Denis Kenzior <denkenz@gmail.com>, linux-wireless@vger.kernel.org
Date:   Fri, 30 Aug 2019 12:19:13 +0200
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References: <20190826162637.7535-1-denkenz@gmail.com>
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On Mon, 2019-08-26 at 11:26 -0500, Denis Kenzior wrote:
> 
> + *	Prior to Kernel 5.4, userspace applications should implement the
> + *	following behavior:

I'm not sure mentioning the kernel version here does us any good? I
mean, you really need to implement that behaviour regardless of kernel
version, if NL80211_EXT_FEATURE_LIVE_IFTYPE_CHANGE isn't set.

> + * @NL80211_EXT_FEATURE_LIVE_IFTYPE_CHANGE: This device supports switching
> + * 	the IFTYPE of an interface without having to bring the device DOWN
> + * 	first via RTNL.  Exact semantics of this feature is driver
> + * 	implementation dependent.  

That's not really nice.

> For mac80211, the following restrictions
> + * 	apply:
> + * 		- Only devices currently in IFTYPE AP, P2P_GO, P2P_CLIENT,
> + * 		  STATION, ADHOC and OCB can be switched.
> + * 		- The target IFTYPE must be one of: AP, P2P_GO, P2P_CLIENT,
> + * 		  STATION, ADHOC or OCB.
> + * 	Other drivers are expected to follow similar restrictions.

Maybe we should instead have a "bitmask of interface types that can be
switched while live" or something like that?

johannes