Re: [PATCH 2/3] hwmon: Add support for SPD5118 compliant temperature sensors

From: Thomas Weißschuh
Date: Fri May 31 2024 - 06:38:14 EST


On 2024-05-31 12:01:35+0000, René Rebe wrote:
> On May 31, 2024, at 11:31, Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx> wrote:
> >>> Wolfgang seems to think it's important:
> >
> > Wolfram, please.

Sorry, Wolfram.

> >
> >>> https://lore.kernel.org/lkml/tdia472d4pow2osabef24y2ujkkquplfajxmmtk5pnxllsdxsz@wxzynz7llasr/
> >>>
> >>
> >> Ok, but that doesn't explain the reason. Wolfram, Paul, why do you
> >> think this is needed ? Note that I am not opposed to adding spd
> >> eeprom support, but I'd like to know why I am doing it before
> >> I spend time on it.
> >
> > A working eeprom driver is needed to get 'decode-dimms' from the
> > i2c-tools package working. Jean reported that EEPROM access for DDR5 is
> > different from DDR4, so it needs a separate driver. And
> > i2c_register_spd() then needs to be updated to use the new driver for
> > DDR5.
>
> Well my original downstream driver already had eeprom access:
>
> https://svn.exactcode.de/t2/trunk/package/kernel/linux/spd-5118.patch
>
> Note there are some surrounding -2, and parity patches around this patch.

That would need to be rewritten to use the nvmem APIs though, I guess.
If nobody wants to do it, I'm volunteering.

Thomas