R: R: R: [PATCH net] net: dsa: mv88e6xxx: continue without PTP if the TAI period is invalid

[Nicolò Giuliani - nicolo.giuliani6@studio.unibo.it]

Hi Andrew,

Thanks, that explains it. I have sent the patch as v2 in a new thread:

https://patch.msgid.link/20260921-send-net-v2-1-031ad720f140@xxxxxxxxxxxxxxx

It adds mv88e6191x_ops, a copy of mv88e6393x_ops without avb_ops and ptp_ops, uses it for the 88E6191X and the 88E6193X and drops ptp_support for both, so the 88E6393X is unchanged. I included the 88E6191X because UMSD describes it the same way; I only have an 88E6193X, so that entry is untested.

I tested it on the 88E6193X of the Sophos XGS 107w (Linux 6.18.52): with the driver unbound and the module replaced by one built with the patch, and without the workaround from v1, the switch is detected as 0x1930, the eight PHYs and the 10gbase-r link come up, there is no PTP error and no PHC is registered.

Thanks,
Nicolo Giuliani

________________________________________
Da: Andrew Lunn <andrew@xxxxxxx>
Inviato: domenica 20 settembre 2026 23:21
A: Nicolò Giuliani - nicolo.giuliani6@xxxxxxxxxxxxxxx
Cc: Vladimir Oltean; David S. Miller; Eric Dumazet; Jakub Kicinski; Paolo Abeni; Richard Cochran; netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
Oggetto: Re: R: R: [PATCH net] net: dsa: mv88e6xxx: continue without PTP if the TAI period is invalid

On Sun, Sep 20, 2026 at 07:08:57PM +0000, Nicolò Giuliani - nicolo.giuliani6@xxxxxxxxxxxxxxx wrote:
> Hi Andrew,
>

> Thanks, that is what I needed. I checked it on the board (chip ID
> 0x1930, so the driver entry is the 88E6193X, family 6393, which uses
> mv88e6390_avb_ops and mv88e6352_ptp_ops):

Marvell names all there devices 88e6xyz. The x indicates the model
within the family y. The lower the value of x, the less features the
device has.

So i could well be the 88E6193X does not have avb, tsn and ptp.

Marvell has a vendor driver for these devices called UMSD. It has an
open source licence, but it is well hidden.

include/driver/msdSysConfig.h:  MSD_88E6193X = 0x193,   /* 88E6193X  - BGA package - No AVB, No Routing, No Cut-through*/

So i would say PTP is not available on this device. Please could you
submit a patch removing the mv88e6390_avb_ops and mv88e6352_ptp_ops.

There is also:

        MSD_88E6191X = 0x192,  /* Amethyst 88E6191X  - BGA package - No AVB, No Routing, No Cut-through, No TCAM, No 802.1BR*/

Maybe you can review that entry as well.

       Andrew