Re: [PATCH net-next 0/3] net: stmmac: add physical port identification support

["Russell King (Oracle)" <linux@armlinux.org.uk>]

See comments on the previous posting of this patch series (why it was
reposted in as little as six minutes apart...)

netdev has a rule: allow 24 hours between re-posts.

netdev has another rule: don't post new material, except for bug fixes
for the net tree, while netdev is closed (in other words, while the
merge window is open.) If you wish to post new material, mark it RFC.

Thanks.

On Thu, Dec 04, 2025 at 04:37:26PM +0000, John Madieu wrote:
> This series adds physical port identification support to the stmmac driver,
> enabling userspace to query hardware-stable identifiers for network interfaces
> via ndo_get_phys_port_id() and ndo_get_phys_port_name().
> 
> On systems with multiple ethernet controllers sharing the same driver,
> physical port identification provides stable identifiers that persist
> across reboots and are independent of interface enumeration order.
> This is particularly useful for predictable network interface naming
> and for correlating interfaces with physical connectors.
> 
> The implementation follows a two-tier approach:
> 
> 1. Generic stmmac support: Default implementations use the permanent MAC
>    address as port ID and bus_id for port naming. This provides immediate
>    benefit for all stmmac-based platforms.
> 
> 2. Glue driver override: Platform drivers can provide custom callbacks
>    for hardware-specific identification schemes. The Renesas GBETH driver
>    implements this to support device tree-based port identification,
>    addressing cases where hardware lacks unique identification registers.
> 
> The Renesas implementation constructs an 8-byte port identifier from:
> - Permanent MAC address (if available) or Renesas OUI (74:90:50) as fallback
> - Port index from device tree property or ethernet alias
> 
> 
> John Madieu (3):
>   net: stmmac: add physical port identification support
>   dt-bindings: net: renesas-gbeth: Add port-id property
>   net: stmmac: dwmac-renesas-gbeth: add physical port identification
> 
>  .../bindings/net/renesas,rzv2h-gbeth.yaml     | 19 +++++++
>  .../stmicro/stmmac/dwmac-renesas-gbeth.c      | 56 +++++++++++++++++++
>  .../net/ethernet/stmicro/stmmac/stmmac_main.c | 54 ++++++++++++++++++
>  include/linux/stmmac.h                        |  5 ++
>  4 files changed, 134 insertions(+)
> 
> -- 
> 2.25.1
> 
> 

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