Re: [PATCH net-next v4] net: sfp: add SMBus I2C block support

On Fri, Jan 16, 2026 at 12:16:11PM +0100, Jonas Jelonek wrote:

Hi Maxime,

On 09.01.26 18:03, Maxime Chevallier wrote:

quoted

ACK, I'll gladly help with testing. This should actually be easily
achievable with a board that has a real i2c interface connected to the
SFP cage, as there's a i2c smbus emulation layer. The SMBus helpers will
work with a true I2C adapter, you may have to tweak the code though.

This is relevant for modules that have a built-in PHY that you can
access, if you don't have any I can run some tests here, I have more
than enough modules...

If you don't have time at all for that, I may give this a shot at some
point, but my time is a bit scarce right now :'(

I'd postpone this part if that's ok. Quite busy at the moment :(

When I come to trying to work on that, should that all be kept in
mdio-i2c.c? I'm asking because we have a downstream implementation
moving that SMbus stuff to mdio-smbus.c. This covers quite a lot right
now, C22/C45 and Rollball, but just with byte access [1]. Because that
isn't my work, I'll need to check with the original authors and adapt this
for an upstream patch, trying to add word + block access.

Kind regards,
Jonas

[1] https://github.com/openwrt/openwrt/blob/66b6791abe6f08dec2924b5d9e9e7dac93f37bc4/target/linux/realtek/patches-6.12/712-net-phy-add-an-MDIO-SMBus-library.patch

My personal view on this is not suitable for sharing publicly. I'm sure
people can guess what my view is and why. (Look at the age of the
patch, and it's clearly "lets re-implement mdio-i2c" rather than "let's
adapt it".

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!