Re: [PATCH net-next] net: dsa: microchip: ksz9477: follow errata sheet when applying fixups

[Simon Horman <simon.horman@corigine.com>]

On Mon, Jun 19, 2023 at 10:16:32AM +0200, Rasmus Villemoes wrote:
> The errata sheets for both ksz9477 and ksz9567 begin with
> 
>   IMPORTANT NOTE
> 
>   Multiple errata workarounds in this document call for changing PHY
>   registers for each PHY port. PHY registers 0x0 to 0x1F are in the
>   address range 0xN100 to 0xN13F, while indirect (MMD) PHY registers
>   are accessed via the PHY MMD Setup Register and the PHY MMD Data
>   Register.
> 
>   Before configuring the PHY MMD registers, it is necessary to set the
>   PHY to 100 Mbps speed with auto-negotiation disabled by writing to
>   register 0xN100-0xN101. After writing the MMD registers, and after
>   all errata workarounds that involve PHY register settings, write
>   register 0xN100-0xN101 again to enable and restart auto-negotiation.
> 
> Without that explicit auto-neg restart, we do sometimes have problems
> establishing link.
> 
> Rather than writing back the hardcoded 0x1340 value the errata sheet
> suggests (which likely just corresponds to the most common strap
> configuration), restore the original value, setting the
> PORT_AUTO_NEG_RESTART bit if PORT_AUTO_NEG_ENABLE is set.
> 
> Fixes: 1fc33199185d ("net: dsa: microchip: Add PHY errata workarounds")
> Cc: stable@vger.kernel.org
> Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
> ---
> While I do believe this is a fix, I don't think it's post-rc7
> material, hence targeting net-next with cc stable.

Hi Rasmus,

unfortunately this does not seem to apply to net-next.
Please consider rebasing and reposting.
Please include Andrew's Reviewed-by tag unless there
are substantial changes (seems unlikely).

-- 
pw-bot: changes-requested