Re: [PATCH 5/6] net: add MV88E61xx DSA driver

[Tim Harvey <tharvey@gateworks.com>]

On Tue, Mar 29, 2022 at 4:22 PM Marek Behún <marek.behun@nic.cz> wrote:
>
> On Tue, 29 Mar 2022 15:52:39 -0700
> Tim Harvey <tharvey@gateworks.com> wrote:
>
> > Add a DSA driver for the MV88E61xx compatible GbE Ethernet switches.
> >
> > Signed-off-by: Tim Harvey <tharvey@gateworks.com>
>

Marek,

Thanks for looking at this.

> Is this final version that should be accepted?

This is the first submission of the new driver.

>
> The drivers seems to support not only 61xx, but 6xxx (6096, 6250, 6352,
> ...).

It should also support all the same devices that the non dsa driver it
was derived from (drivers/net/phy/mv88e61xx.c) but I only have a board
with 88E6176 to test with.

It is not completely clear to me what devices are supported in the
original driver per Kconfig but from looking over the code I would say
the following appear to be supported:
mv88e6096
mv88e6097
mv88e6020
mv88e6070
mv88e6071
mv88e6172
mv88e6176
mv88e6220
mv88e6240
mv88e6250
mv88e6352

>
> Also there are some commented lines, for example
>
> > +//   u16 port_stat_link_mask;/* Bitmask for port link status bits */
> > +//   u16 port_stat_dup_mask; /* Bitmask for port duplex status bits */
> > +//   u8 port_stat_speed_width;/* Width of speed status bitfield */
>
> What is their purpose?
>

oops... that was a mistake. I'm surprised checkpatch didn't catch
those. Those were in the non-dsa driver and not used here so will be
removed.

> Why is mv88e61xx_dsa_xmit() no-op?

For DSA dsa-uclass calls the switch master eth device send function
after calling the dsa_ops->xmit function so that a dsa driver can add
any header/footer if needed. The function is required but in my case I
don't care about header/footer tagging or vlan as only 1 port is
active at a time in U-Boot so I just return success.

Best Regards,

Tim