Re: [PATCH net v3 0/3] net: stmmac: L3/L4 filter bug fixes

[Jakub Raczynski]

On Mon, Jul 13, 2026 at 07:37:12PM -0700, muhammad.nazim.amirul.nazle.asmade@xxxxxxxxxx wrote:
> From: Nazim Amirul <muhammad.nazim.amirul.nazle.asmade@xxxxxxxxxx>
> 
> This series fixes three bugs in the stmmac L3/L4 TC flower filter
> implementation for the XGMAC2 core. All three patches target net.
> 
> The L3/L4 filter match count statistics patch (originally patch 4/4)
> has been split out and will be sent separately against net-next per
> Andrew Lunn's review of v1.
> 
> Patch 1 fixes a register corruption bug in the L4 filter port configuration.
> The XGMAC_L4_ADDR register holds both source and destination port match
> values in a single register. The original code overwrites the entire register
> when setting either field, silently erasing the other. This is fixed by
> using a read-modify-write sequence.
> 
> Patch 2 fixes the basic flow match parser to properly reject unsupported
> offload requests with -EOPNOTSUPP instead of silently accepting them.
> Unsupported cases include partial protocol masks, non-IPv4 network proto,
> and non-TCP/UDP transport proto. Extack messages are now included so users
> know exactly which part of the match is unsupported. The -EOPNOTSUPP is
> also now returned directly instead of using break, which was silently
> discarding the error on FLOW_CLS_REPLACE operations.
> 
> Patch 3 fixes a stale action bug on filter deletion. When a filter entry
> with a drop action is deleted, the action field was not reset, causing
> it to persist and potentially affect subsequent filter configurations.
> 
> All three patches fix the original L3/L4 filter implementation introduced in
> 425eabddaf0f ("net: stmmac: Implement L3/L4 Filters using TC Flower").
> 
> Changes in v3:
> - Patch 2: add extack messages to each -EOPNOTSUPP return (Jakub Kicinski)
> - Patch 2: return -EOPNOTSUPP directly instead of break to avoid silently
>   reporting success on unsupported FLOW_CLS_REPLACE (Sashiko review)
> 
> Changes in v2:
> - Split patch 4/4 (ethtool stats) out to net-next per Andrew Lunn's review
> 
> Nazim Amirul (3):
>   net: stmmac: xgmac: fix l4 filter port overwrite on register update
>   net: stmmac: fix l3l4 filter rejecting unsupported offload requests
>   net: stmmac: reset residual action in L3L4 filters on delete
> 
>  .../ethernet/stmicro/stmmac/dwxgmac2_core.c   | 28 ++++++++-------
>  .../net/ethernet/stmicro/stmmac/stmmac_tc.c   | 35 +++++++++++++++++++
>  2 files changed, 51 insertions(+), 12 deletions(-)
>

I think you probably should have done [PATCH RESEND] and it looks bit
funky on mailing list (double cover letter ?), but is fine on patchwork.

One nit:
- Not sure EOPNOTSUPP is optimal, as this is just wrong config and maybe
  something like EINVAL would be better? But thats whatever

I have no means to test this now, but 1st patch seems to solve lot of
encountered issues.

For the series:
Reviewed-by: Jakub Raczynski <j.raczynski@xxxxxxxxxxx>

BR
Jakub Raczynski