Re: [PATCH 1/3] net: pse-pd: tps23881: Fix current measurement scaling

Kory Maincent
2025-10-06T12:50:35Z

On Sat, 4 Oct 2025 20:03:49 +0200
Thomas Wismer <thomas@wismer.xyz> wrote:

> From: Thomas Wismer <thomas.wismer@scs.ch>
>
> The TPS23881 improves on the TPS23880 with current sense resistors reduced
> from 255 mOhm to 200 mOhm. This has a direct impact on the scaling of the
> current measurement. However, the latest TPS23881 data sheet from May 2023
> still shows the scaling of the TPS23880 model.

Didn't know that. Where did you get that new current step value if it's not
from the datasheet?

Also as the value reported was wrong maybe we need a fix tag here and send it
to net instead of net-next.

> Signed-off-by: Thomas Wismer <thomas.wismer@scs.ch>
> ---
> drivers/net/pse-pd/tps23881.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/pse-pd/tps23881.c b/drivers/net/pse-pd/tps23881.c
> index 63f8f43062bc..b724b222ab44 100644
> --- a/drivers/net/pse-pd/tps23881.c
> +++ b/drivers/net/pse-pd/tps23881.c
> @@ -62,7 +62,7 @@
> #define TPS23881_REG_SRAM_DATA 0x61
>
> #define TPS23881_UV_STEP 3662
> -#define TPS23881_NA_STEP 70190
> +#define TPS23881_NA_STEP 89500
> #define TPS23881_MW_STEP 500
> #define TPS23881_MIN_PI_PW_LIMIT_MW 2000
>

--
Köry Maincent, Bootlin
Embedded Linux and kernel engineering