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Subject: Re: [RFC net] net: dsa: Add missing reference counting
To:     Vivien Didelot <vivien.didelot@gmail.com>
Cc:     netdev@vger.kernel.org, olteanv@gmail.com,
        Andrew Lunn <andrew@lunn.ch>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        open list <linux-kernel@vger.kernel.org>
References: <20200505210253.20311-1-f.fainelli@gmail.com>
 <20200505172302.GB1170406@t480s.localdomain>
From:   Florian Fainelli <f.fainelli@gmail.com>
Message-ID: <d681a82b-5d4b-457f-56de-3a439399cb3d@gmail.com>
Date:   Wed, 6 May 2020 14:24:14 -0700
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On 5/5/2020 2:23 PM, Vivien Didelot wrote:
> On Tue,  5 May 2020 14:02:53 -0700, Florian Fainelli <f.fainelli@gmail.com> wrote:
>> If we are probed through platform_data we would be intentionally
>> dropping the reference count on master after dev_to_net_device()
>> incremented it. If we are probed through Device Tree,
>> of_find_net_device() does not do a dev_hold() at all.
>>
>> Ensure that the DSA master device is properly reference counted by
>> holding it as soon as the CPU port is successfully initialized and later
>> released during dsa_switch_release_ports(). dsa_get_tag_protocol() does
>> a short de-reference, so we hold and release the master at that time,
>> too.
>>
>> Fixes: 83c0afaec7b7 ("net: dsa: Add new binding implementation")
>> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
> 
> Reviewed-by: Vivien Didelot <vivien.didelot@gmail.com>
> 
Andrew, Vladimir, any thoughts on that?
-- 
Florian