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Date:   Thu, 6 Apr 2023 19:02:08 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     linux@armlinux.org.uk
Cc:     Ivan Bornyakov <i.bornyakov@metrotek.ru>, netdev@vger.kernel.org,
        andrew@lunn.ch, hkallweit1@gmail.com, davem@davemloft.net,
        edumazet@google.com, pabeni@redhat.com,
        linux-kernel@vger.kernel.org, system@metrotek.ru,
        stable@vger.kernel.org
Subject: Re: [PATCH net] net: sfp: initialize sfp->i2c_block_size at sfp
 allocation
Message-ID: <20230406190208.7918c71e@kernel.org>
In-Reply-To: <20230405153900.747-1-i.bornyakov@metrotek.ru>
References: <20230405153900.747-1-i.bornyakov@metrotek.ru>
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On Wed,  5 Apr 2023 18:39:00 +0300 Ivan Bornyakov wrote:
> sfp->i2c_block_size is initialized at SFP module insertion in
> sfp_sm_mod_probe(). Because of that, if SFP module was not inserted
> since boot, ethtool -m leads to zero-length I2C read attempt.
> 
>   # ethtool -m xge0
>   i2c i2c-3: adapter quirk: no zero length (addr 0x0050, size 0, read)
>   Cannot get Module EEPROM data: Operation not supported
> 
> If SFP module was plugged then removed at least once,
> sfp->i2c_block_size will be initialized and ethtool -m will fail with
> different error
> 
>   # ethtool -m xge0
>   Cannot get Module EEPROM data: Remote I/O error
> 
> Fix this by initializing sfp->i2_block_size at struct sfp allocation
> stage so ethtool -m with SFP module removed will fail the same way, i.e.
> -EREMOTEIO, in both cases and without errors from I2C adapter.

Hi Russell - yes / no / come back when both patches are ready?