[PATCH net v2 0/2] net: macb: fix the link speed the taprio setup reads

[Aleksei Sviridkin <f@lex.la>]

Two small fixes in macb_taprio_setup_replace(), both in how it obtains
the link speed it scales the schedule with.

The first: it hands phylink_ethtool_ksettings_get() a stack variable
it never zeroed, while phylink fills only what the link mode provides
and even reads one field back from the caller. The second: the speed
check is written as "<= 0" on a u32, so SPEED_UNKNOWN passes it and
turns into a 1 ns hardware limit that every entry then exceeds.

Compile-tested against net; the driver has no test surface, and no
macb board here.

---
v2: both commit messages rewritten to name the uninitialised-memory
    case first and the link-down case as the one that happens; the
    grown declaration keeps reverse xmas tree order; the error text is
    "Invalid speed %d, link-down?" (Théo Lebrun). ethtool_validate_speed()
    was considered for the check and does not fit: it accepts
    SPEED_UNKNOWN by definition, which is exactly the value patch 2
    rejects (Andrew Lunn).
    https://lore.kernel.org/netdev/20260902080528.2211468-1-f@lex.la/


Aleksei Sviridkin (2):
  net: macb: zero the link settings taprio reads back
  net: macb: reject an unknown link speed in the taprio setup

 drivers/net/ethernet/cadence/macb_main.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

-- 
2.53.0