Re: [PATCH net-next v4 02/15] net: dsa: vsc73xx: convert to PHYLINK

Paweł Dembicki
2024-02-14T12:56:22Z

śr., 14 lut 2024 o 00:19 Florian Fainelli <f.fainelli@gmail.com> napisał(a):
>
> On 2/13/24 14:03, Pawel Dembicki wrote:
> > This patch replaces the adjust_link api with the phylink apis that provide
> > equivalent functionality.
> >
> > The remaining functionality from the adjust_link is now covered in the
> > phylink_mac_link_* and phylink_mac_config.
> >
> > Removes:
> > .adjust_link
> > Adds:
> > .phylink_mac_config
> > .phylink_mac_link_up
> > .phylink_mac_link_down
>
> The implementation of phylink_mac_link_down() strictly mimics what had
> been done by adjust_link() in the phydev->link == 0 case, but it really
> makes me wonder whether some bits do not logically belong to
> phylink_mac_link_up(), like "Accept packets again" for instance.
>
> Are we certain there was not an assumption before that we would get
> adjust_link() called first with phydev->link = 0, and then phydev->link
> =1 and that this specific sequence would program things just the way we
> want?

Yes, it was the simplest conversion possible, without any improvements.

Some part is implementation of datasheet (description of ARBEMPTY register):

/* Discard packets */
vsc73xx_update_bits(vsc, VSC73XX_BLOCK_ARBITER, 0,
VSC73XX_ARBDISC, BIT(port), BIT(port));

/* Wait until queue is empty */
ret = read_poll_timeout(vsc73xx_read, err, err < 0 || (val & BIT(port)),
1000, 10000, false, vsc, VSC73XX_BLOCK_ARBITER,
0, VSC73XX_ARBEMPTY, &val);
if (ret)
dev_err(vsc->dev,
"timeout waiting for block arbiter\n");
else if (err < 0)
dev_err(vsc->dev, "error reading arbiter\n");

/* Put this port into reset */
vsc73xx_write(vsc, VSC73XX_BLOCK_MAC, port, VSC73XX_MAC_CFG,
VSC73XX_MAC_CFG_RESET);

I agree that VSC73XX_ARBDISC should be moved to phylink_mac_link_up.
Other things could be optimised and it needs more care. (eg. This
implementation doesn't disable phy when the interface goes down.) I
plan to tweak it after the driver becomes usable. Please let me know
if it should be fixed in this patch.

--
Best Regards,
Pawel Dembicki