Re: [net-next RFC PATCH v3 3/4] net: phy: Add support for Aeonsemi AS21xxx PHYs
From: Christian Marangi
Date: Thu Mar 27 2025 - 07:37:14 EST
On Thu, Mar 27, 2025 at 12:30:42PM +0100, Christian Marangi wrote:
> On Thu, Mar 27, 2025 at 11:24:26AM +0000, Russell King (Oracle) wrote:
> > On Thu, Mar 27, 2025 at 12:35:03AM +0100, Christian Marangi wrote:
> > > +static int as21xxx_match_phy_device(struct phy_device *phydev,
> > > + const struct phy_driver *phydrv)
> > > +{
> > > + struct as21xxx_priv *priv;
> > > + u32 phy_id;
> > > + int ret;
> > > +
> > > + /* Skip PHY that are not AS21xxx or already have firmware loaded */
> > > + if (phydev->c45_ids.device_ids[MDIO_MMD_PCS] != PHY_ID_AS21XXX)
> > > + return phydev->phy_id == phydrv->phy_id;
> >
> > Isn't phydev->phy_id zero here for a clause 45 PHY? If the firmware
> > has been loaded, I believ eyou said that PHY_ID_AS21XXX won't be
> > used, so the if() will be true, and because we've read clause 45
> > IDs, phydev->phy_id will be zero meaning this will never match. So
> > a PHY with firmware loaded won't ever match any of these drivers.
> > This is probably not what you want.
>
> You are right. I will generalize the function to skip having to redo the
> logic. With FW loaded either c45 and c22 ID are filled in.
>
> >
> > I'd suggest converting the tail of phy_bus_match() so that you can
> > call that to do the standard matching using either C22 or C45 IDs
> > as appropriate without duplicating that code.
> >
> > > +
> > > + /* Read PHY ID to handle firmware just loaded */
> > > + ret = phy_read_mmd(phydev, MDIO_MMD_PCS, MII_PHYSID1);
> > > + if (ret < 0)
> > > + return ret;
> > > + phy_id = ret << 16;
> > > +
> > > + ret = phy_read_mmd(phydev, MDIO_MMD_PCS, MII_PHYSID2);
> > > + if (ret < 0)
> > > + return ret;
> > > + phy_id |= ret;
> > > +
> > > + /* With PHY ID not the generic AS21xxx one assume
> > > + * the firmware just loaded
> > > + */
> > > + if (phy_id != PHY_ID_AS21XXX)
> > > + return phy_id == phydrv->phy_id;
> > > +
> > > + /* Allocate temp priv and load the firmware */
> > > + priv = kzalloc(sizeof(*priv), GFP_KERNEL);
> > > + if (!priv)
> > > + return -ENOMEM;
> > > +
> > > + mutex_init(&priv->ipc_lock);
> > > +
> > > + ret = aeon_firmware_load(phydev);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + ret = aeon_ipc_sync_parity(phydev, priv);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + /* Enable PTP clk if not already Enabled */
> > > + ret = phy_set_bits_mmd(phydev, MDIO_MMD_VEND1, VEND1_PTP_CLK,
> > > + VEND1_PTP_CLK_EN);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + ret = aeon_dpc_ra_enable(phydev, priv);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + mutex_destroy(&priv->ipc_lock);
> > > + kfree(priv);
> > > +
> > > + /* Return not maching anyway as PHY ID will change after
> > > + * firmware is loaded.
> >
> > Also "This relies on the driver probe order."
> >
> > > + */
> > > + return 0;
> > > +}
> > > +
> > > +static struct phy_driver as21xxx_drivers[] = {
> > > + {
> > > + /* PHY expose in C45 as 0x7500 0x9410
> > > + * before firmware is loaded.
> >
> > Also "This driver entry must be attempted first to load the firmware and
> > thus update the ID registers."
> >
> > > + */
> > > + PHY_ID_MATCH_EXACT(PHY_ID_AS21XXX),
> > > + .name = "Aeonsemi AS21xxx",
> > > + .match_phy_device = as21xxx_match_phy_device,
> > > + },
> > > + {
> > > + PHY_ID_MATCH_EXACT(PHY_ID_AS21011JB1),
> > > + .name = "Aeonsemi AS21011JB1",
> > > + .probe = as21xxx_probe,
> > > + .match_phy_device = as21xxx_match_phy_device,
> > > + .read_status = as21xxx_read_status,
> > > + .led_brightness_set = as21xxx_led_brightness_set,
> > > + .led_hw_is_supported = as21xxx_led_hw_is_supported,
> > > + .led_hw_control_set = as21xxx_led_hw_control_set,
> > > + .led_hw_control_get = as21xxx_led_hw_control_get,
> > > + .led_polarity_set = as21xxx_led_polarity_set,
> >
> > If I'm reading these driver entries correctly, the only reason for
> > having separate entries is to be able to have a unique name printed
> > for each - the methods themselves are all identical.
> >
> > My feeling is that is not a sufficient reason to duplicate the driver
> > entries, which adds bloat (not only in terms of static data, but also
> > the data structures necessary to support each entry in sysfs.) However,
> > lets see what Andrew says.
> >
>
> If you remember that was one of my crazy project in trying to reduce the
> array but I remember it did end up bad or abbandoned with the problem of
> having to reinvent each PHY. Probably my changes caused too much patch
> delta.
>
> The proposal was exactly to pack all the struct that have similar OPs
> with introducing an array of PHY ID for each driver.
>
Found the old series. [1]
[1] https://lore.kernel.org/all/20240218190034.15447-1-ansuelsmth@xxxxxxxxx/
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