net: dsa: mv88e6xxx: 88E6191X and 88E6193X have no PTP

The 88E6191X and 88E6193X are 6393 family devices that share
mv88e6393x_ops with the 88E6393X and are marked as ptp_support. Marvell's
UMSD driver describes both as parts without AVB (88E6193X: "BGA package -
No AVB, No Routing, No Cut-through"), and the register access confirms it
on an 88E6193X: the whole indirect AVB register space behind Global 2
registers 0x16 and 0x17 reads zero, for every port, block and address,
with the 6390 and with the 6352 command encoding. Writes to the TAI
registers, including the clock period register and the TAI global
configuration register, read back as zero.

Since commit 7e3c18097a70 ("net: dsa: mv88e6xxx: read cycle counter
period from hardware") the PTP setup reads the TAI clock period, so the
switch fails to probe:

mv88e6xxx ...: unexpected cycle counter period of 0 ps

Add mv88e6191x_ops, a copy of mv88e6393x_ops without avb_ops and ptp_ops,
use it for the 88E6191X and the 88E6193X and stop setting ptp_support for
them. The 88E6393X is unchanged.

Tested on an 88E6193X (Sophos XGS 107w): the switch probes and the ports
work. I do not have an 88E6191X, it is changed because UMSD describes it
the same way.

Fixes: de776d0d316f ("net: dsa: mv88e6xxx: add support for mv88e6393x family")
Suggested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Nicolo Giuliani <nicolo.giuliani6@studio.unibo.it>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20260921-send-net-v2-1-031ad720f140@studio.unibo.it
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

0 files changed, 0 insertions, 0 deletions