RE: [RFC PATCH net-next 1/9] ethtool: Add ethtool operation to write to a transceiver module EEPROM

From: Danielle Ratson <danieller@nvidia.com>
To: Andrew Lunn <andrew@lunn.ch>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
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	mlxsw <mlxsw@nvidia.com>, Petr Machata <petrm@nvidia.com>,
	Ido Schimmel <idosch@nvidia.com>
Subject: RE: [RFC PATCH net-next 1/9] ethtool: Add ethtool operation to write to a transceiver module EEPROM
Date: Tue, 30 Jan 2024 07:43:01 +0000	[thread overview]
Message-ID: <DM6PR12MB451687F0408B3114DCAA7DC9D87D2@DM6PR12MB4516.namprd12.prod.outlook.com> (raw)
In-Reply-To: <20ab7355-fc72-4dba-b3ea-db2244909bab@lunn.ch>

> > On Mon, Jan 22, 2024 at 10:45:22AM +0200, Danielle Ratson wrote:
> > > From: Ido Schimmel <idosch@nvidia.com>
> > >
> > > Ethtool can already retrieve information from a transceiver module
> > > EEPROM by invoking the ethtool_ops::get_module_eeprom_by_page
> operation.
> > > Add a corresponding operation that allows ethtool to write to a
> > > transceiver module EEPROM.
> > >
> > > The purpose of this operation is not to enable arbitrary read /
> > > write access, but to allow the kernel to write to specific addresses
> > > as part of transceiver module firmware flashing. In the future, more
> > > functionality can be implemented on top of these read / write
> > > operations.
> >
> > My memory is dim, but i thought we decided that since the algorithm to
> > program these modules is defined in the standard, all we need to do is
> > pass the firmware blob, and have an in kernel implementation of the
> > algorithm. There is no need to have an arbitrary write blob to module,
> > which might, or might not be abused in the future.
> 
> O.K, back after reading more of the patches.
> 
> If i'm understanding the code correctly, this is never exposed to userspace? Its
> purely an in kernel API? It would be good to make that clear in the commit
> message, and document that in the ethtool ops structure.
> 
> Thanks
>       Andrew

Hi Andrew,

Yes, that is correct.
Will add a clarification.

Thanks.