Re: [PATCH net-next v9 08/15] net: mdiobus: Introduce fwnode_mdiobus_register_phy()

[andy@surfacebook.localdomain]

Fri, Jun 11, 2021 at 01:53:54PM +0300, Ioana Ciornei kirjoitti:
> From: Calvin Johnson <calvin.johnson@oss.nxp.com>
> 
> Introduce fwnode_mdiobus_register_phy() to register PHYs on the
> mdiobus. From the compatible string, identify whether the PHY is
> c45 and based on this create a PHY device instance which is
> registered on the mdiobus.
> 
> Along with fwnode_mdiobus_register_phy() also introduce
> fwnode_find_mii_timestamper() and fwnode_mdiobus_phy_device_register()
> since they are needed.
> While at it, also use the newly introduced fwnode operation in
> of_mdiobus_phy_device_register().

I understand that this patch series is applied, but I think we have a problem
that has to be fixed before the release. See below for the details.

...

> +int fwnode_mdiobus_phy_device_register(struct mii_bus *mdio,
> +				       struct phy_device *phy,
> +				       struct fwnode_handle *child, u32 addr)
> +{
> +	int rc;
> +
> +	rc = fwnode_irq_get(child, 0);
> +	if (rc == -EPROBE_DEFER)
> +		return rc;
> +
> +	if (rc > 0) {
> +		phy->irq = rc;
> +		mdio->irq[addr] = rc;
> +	} else {
> +		phy->irq = mdio->irq[addr];
> +	}
> +
> +	if (fwnode_property_read_bool(child, "broken-turn-around"))
> +		mdio->phy_ignore_ta_mask |= 1 << addr;
> +
> +	fwnode_property_read_u32(child, "reset-assert-us",
> +				 &phy->mdio.reset_assert_delay);
> +	fwnode_property_read_u32(child, "reset-deassert-us",
> +				 &phy->mdio.reset_deassert_delay);
> +
> +	/* Associate the fwnode with the device structure so it
> +	 * can be looked up later
> +	 */

> +	fwnode_handle_get(child);

We take a reference counting here.
Who and when should drop it?

> +	phy->mdio.dev.fwnode = child;
> +
> +	/* All data is now stored in the phy struct;
> +	 * register it
> +	 */
> +	rc = phy_device_register(phy);
> +	if (rc) {
> +		fwnode_handle_put(child);
> +		return rc;
> +	}
> +
> +	dev_dbg(&mdio->dev, "registered phy %p fwnode at address %i\n",
> +		child, addr);
> +	return 0;
> +}
> +EXPORT_SYMBOL(fwnode_mdiobus_phy_device_register);
> +
> +int fwnode_mdiobus_register_phy(struct mii_bus *bus,
> +				struct fwnode_handle *child, u32 addr)
> +{
> +	struct mii_timestamper *mii_ts = NULL;
> +	struct phy_device *phy;
> +	bool is_c45 = false;
> +	u32 phy_id;
> +	int rc;
> +
> +	mii_ts = fwnode_find_mii_timestamper(child);
> +	if (IS_ERR(mii_ts))
> +		return PTR_ERR(mii_ts);
> +
> +	rc = fwnode_property_match_string(child, "compatible",
> +					  "ethernet-phy-ieee802.3-c45");
> +	if (rc >= 0)
> +		is_c45 = true;
> +
> +	if (is_c45 || fwnode_get_phy_id(child, &phy_id))
> +		phy = get_phy_device(bus, addr, is_c45);
> +	else
> +		phy = phy_device_create(bus, addr, phy_id, 0, NULL);
> +	if (IS_ERR(phy)) {
> +		unregister_mii_timestamper(mii_ts);
> +		return PTR_ERR(phy);
> +	}
> +
> +	if (is_acpi_node(child)) {
> +		phy->irq = bus->irq[addr];
> +
> +		/* Associate the fwnode with the device structure so it
> +		 * can be looked up later.
> +		 */
> +		phy->mdio.dev.fwnode = child;
> +
> +		/* All data is now stored in the phy struct, so register it */
> +		rc = phy_device_register(phy);
> +		if (rc) {
> +			phy_device_free(phy);

> +			fwnode_handle_put(phy->mdio.dev.fwnode);

We dropped reference counting here, but who and when acquired it?

> +			return rc;
> +		}
> +	} else if (is_of_node(child)) {
> +		rc = fwnode_mdiobus_phy_device_register(bus, phy, child, addr);
> +		if (rc) {
> +			unregister_mii_timestamper(mii_ts);
> +			phy_device_free(phy);
> +			return rc;
> +		}
> +	}
> +
> +	/* phy->mii_ts may already be defined by the PHY driver. A
> +	 * mii_timestamper probed via the device tree will still have
> +	 * precedence.
> +	 */
> +	if (mii_ts)
> +		phy->mii_ts = mii_ts;
> +	return 0;
> +}

-- 
With Best Regards,
Andy Shevchenko