[PATCH net v3 0/3] net: dsa: mv88e6xxx: 6141/6341 workarounds

[Luke Howard]

This patch series addresses three issues I found with the 88E6341
switch, which likely also apply to the 88E6141 (which is the same
chip without AVB/TSN support).

The first was a genuine bug, which assumed the chip did not have
a dedicated ATU FID register (it does).

The second is an issue I noticed with hash collisions in the ATU
on the 6341 when using multiple FIDs. Different algorithms could
be selected using devlink, but the FDB was not flushed which
resulted in a corrupted FDB. (There is an outstanding question
as to whether this should only be allowed when all user ports
are administratively down; this is not addressed in this revision.)

The third is an issue (not originally included in the first two
revisions of this patch series) where flushing a FDB entry would
instead move it to port 3.

Signed-off-by: Luke Howard <lukeh@xxxxxxxx>
---
Changes in v3:
- Don't reorder mv88e6xxx_info to optimize alignment; just add
  atu_fid_reg
- Don't clip ATU Move ToPort delete sentinel (flushing learned
  FDB entries was broken)
- Link to v2: https://patch.msgid.link/20260710-mv88e6x41-fixes-v2-0-e23654c65aa0@xxxxxxxx

Changes in v2:
- Rather than special casing ATU hash algorithm for the 6341, simply
  ensure the ATU is flushed when changing it via devlink.
- Retartget net instead of net-next, as this is a bugfix
- Link to v1: https://patch.msgid.link/20260703-mv88e6x41-fixes-v1-0-fbd3a1bf8965@xxxxxxxx

To: Andrew Lunn <andrew@xxxxxxx>
To: Vladimir Oltean <olteanv@xxxxxxxxx>
To: "David S. Miller" <davem@xxxxxxxxxxxxx>
To: Eric Dumazet <edumazet@xxxxxxxxxx>
To: Jakub Kicinski <kuba@xxxxxxxxxx>
To: Paolo Abeni <pabeni@xxxxxxxxxx>
To: Richard Cochran <richardcochran@xxxxxxxxx>
To: Vivien Didelot <vivien.didelot@xxxxxxxxx>
To: Gregory CLEMENT <gregory.clement@xxxxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx

---
Luke Howard (3):
      net: dsa: mv88e6xxx: write the ATU FID register on 88E6141/88E6341
      net: dsa: mv88e6xxx: flush the ATU when the hash algorithm changes
      net: dsa: mv88e6xxx: don't clip ATU Move ToPort delete sentinel

 drivers/net/dsa/mv88e6xxx/chip.c        | 29 ++++++++++++++++++++++++++++-
 drivers/net/dsa/mv88e6xxx/chip.h        |  5 +++++
 drivers/net/dsa/mv88e6xxx/devlink.c     |  6 ++++++
 drivers/net/dsa/mv88e6xxx/global1_atu.c | 11 ++++++++---
 4 files changed, 47 insertions(+), 4 deletions(-)
---
base-commit: f6f3b36c15ed44de1fbb44e645e4fae8c4a4453e
change-id: 20260624-mv88e6x41-fixes-d4c84f955ebc

Best regards,
--  
Luke Howard <lukeh@xxxxxxxx>