Date:   Thu, 9 Feb 2023 13:07:25 -0800
From:   Jakub Kicinski <kuba@kernel.org>
To:     <Ajay.Kathat@microchip.com>
Cc:     <heiko.thiery@gmail.com>, <Claudiu.Beznea@microchip.com>,
        <kvalo@kernel.org>, <linux-wireless@vger.kernel.org>,
        <michael@walle.cc>, <netdev@vger.kernel.org>,
        <Amisha.Patel@microchip.com>
Subject: Re: wilc1000 MAC address is 00:00:00:00:00:00
Message-ID: <20230209130725.0b04a424@kernel.org>
In-Reply-To: <51134d12-1b06-6d6f-e798-7dd681a8f3ae@microchip.com>
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        <e027bfcf-1977-f2fa-a362-8faed91a19f9@microchip.com>
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        <51134d12-1b06-6d6f-e798-7dd681a8f3ae@microchip.com>
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On Thu, 9 Feb 2023 18:51:58 +0000 Ajay.Kathat@microchip.com wrote:
> > netdev should be created with a valid lladdr, is there something
> > wifi-specific here that'd prevalent that? The canonical flow is
> > to this before registering the netdev:
> 
> Here it's the timing in wilc1000 by when the MAC address is available to
> read from NV. NV read is available in "mac_open" net_device_ops instead
> of bus probe function. I think, mostly the operations on netdev which
> make use of mac address are performed after the "mac_open" (I may be
> missing something).
> 
> Does it make sense to assign a random address in probe and later read
> back from NV in mac_open to make use of stored value?

Hard to say, I'd suspect that may be even more confusing than
starting with zeroes. There aren't any hard rules around the
addresses AFAIK, but addrs are visible to user space. So user
space will likely make assumptions based on the most commonly 
observed sequence (reading real addr at probe).