Subject: Re: [PATCH v2] eeprom/optoe: driver to read/write SFP/QSFP/CMIS EEPROMS

From: Andrew Lunn <[email-masked]>
Date: Fri, 26 Feb 2021 23:34:39 +0100

On Mon, Feb 15, 2021 at 11:38:21AM -0800, Don Bollinger wrote:
> optoe is an i2c based driver that supports read/write access to all
> the pages (tables) of MSA standard SFP and similar devices (conforming
> to the SFF-8472 spec), MSA standard QSFP and similar devices (conforming
> to the SFF-8636 spec) and CMIS and similar devices (conforming to the
> Common Management Interface Specfication).

Hi Don

Please make sure you Cc: netdev. This is networking stuff.

And we have seen this code before, and the netdev Maintainers have
argued against it before.

> These devices provide identification, operational status and control
> registers via an EEPROM model.  These devices support one or 3 fixed pages
> (128 bytes) of data, and one page that is selected via a page register on
> the first fixed page.  Thus the driver's main task is to map these pages
> onto a simple linear address space for user space management applications.
> See the driver code for a detailed layout.

I assume you have seen the work NVIDIA submitted last week? This idea
of linear pages is really restrictive and we are moving away from it.

> The EEPROM data is accessible to user space and kernel consumers via the
> nvmem interface.

ethtool -m ?

In the past, this code has been NACKed because it does not integrate
into the networking stack. Is this attempt any different?

Thanks
	Andrew