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Subject: Re: [PATCH] net: wireless: Add module_param(mac_prefix) to
 mac80211_hwsim
From:   Marcel Holtmann <marcel@holtmann.org>
In-Reply-To: <20200302234946.75425-1-rkir@google.com>
Date:   Tue, 3 Mar 2020 07:35:25 +0100
Cc:     Johannes Berg <johannes@sipsolutions.net>,
        linux-wireless@vger.kernel.org, lfy@google.com
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To:     rkir@google.com
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Hi Roman,

> By default mac80211_hwsim creates N radios with
> MAC addresses like '02:00:00:nn:nn:00' where nnnn
> is incremented.
> 
> We (Android Studio Emulator) need a way to have unique
> MAC addresses. Currently in mac80211_hwsim this can
> be done by sending HWSIM_CMD_DEL_RADIO and
> HWSIM_CMD_NEW_RADIO commands.
> 
> The 'mac_prefix' parameter provides an easier way to
> make MAC address unique by specifying two octets in
> MAC address, i.e. '02:pp:pp:nn:nn:00'.

since we have an API for creating radios, wouldn’t it be better to add a kernel option to allow setting the default number of radios on module load to 0 and then let userspace create them on demand. I for example always set my testing kernel to load 0 radios.

Regards

Marcel