> -----Original Message-----
> From: Calvin Johnson (OSS) <calvin.john...@oss.nxp.com>
> Sent: Monday, June 22, 2020 11:19 AM
> To: Jeremy Linton <jeremy.lin...@arm.com>; Russell King - ARM Linux admin
> <li...@armlinux.org.uk>; Jon <j...@solid-run.com>; Cristi Sovaiala
> <cristian.sovai...@nxp.com>; Ioana Ciornei <ioana.cior...@nxp.com>; Andrew
> Lunn <and...@lunn.ch>; Andy Shevchenko <andy.shevche...@gmail.com>;
> Florian Fainelli <f.faine...@gmail.com>; Madalin Bucur (OSS)
> <madalin.bu...@oss.nxp.com>
> Cc: linux...@gmail.com; netdev@vger.kernel.org; Calvin Johnson (OSS)
> <calvin.john...@oss.nxp.com>
> Subject: [net-next PATCH v2 1/3] net: phy: Allow mdio buses to auto-probe
> c45 devices
>
> From: Jeremy Linton <jeremy.lin...@arm.com>
>
> The mdiobus_scan logic is currently hardcoded to only
> work with c22 devices. This works fairly well in most
> cases, but its possible that a c45 device doesn't respond
> despite being a standard phy. If the parent hardware
> is capable, it makes sense to scan for c22 devices before
> falling back to c45.
>
> As we want this to reflect the capabilities of the STA,
> lets add a field to the mii_bus structure to represent
> the capability. That way devices can opt into the extended
> scanning. Existing users should continue to default to c22
> only scanning as long as they are zero'ing the structure
> before use.
How is this default working for existing users, the code below does not seem
to do anything for a zeroed struct, as there is no default in the switch?
>
> Signed-off-by: Jeremy Linton <jeremy.lin...@arm.com>
> Signed-off-by: Calvin Johnson <calvin.john...@oss.nxp.com>
>
> ---
>
> Changes in v2:
> - Reserve "0" to mean that no mdiobus capabilities have been declared.
>
> drivers/net/phy/mdio_bus.c | 17 +++++++++++++++--
> include/linux/phy.h | 8 ++++++++
> 2 files changed, 23 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
> index 6ceee82b2839..e6c179b89907 100644
> --- a/drivers/net/phy/mdio_bus.c
> +++ b/drivers/net/phy/mdio_bus.c
> @@ -739,10 +739,23 @@ EXPORT_SYMBOL(mdiobus_free);
> */
> struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
> {
> - struct phy_device *phydev;
> + struct phy_device *phydev = ERR_PTR(-ENODEV);
> int err;
>
> - phydev = get_phy_device(bus, addr, false);
> + switch (bus->probe_capabilities) {
> + case MDIOBUS_C22:
> + phydev = get_phy_device(bus, addr, false);
> + break;
> + case MDIOBUS_C45:
> + phydev = get_phy_device(bus, addr, true);
> + break;
> + case MDIOBUS_C22_C45:
> + phydev = get_phy_device(bus, addr, false);
> + if (IS_ERR(phydev))
> + phydev = get_phy_device(bus, addr, true);
> + break;
> + }
> +
> if (IS_ERR(phydev))
> return phydev;
>
> diff --git a/include/linux/phy.h b/include/linux/phy.h
> index 9248dd2ce4ca..7860d56c6bf5 100644
> --- a/include/linux/phy.h
> +++ b/include/linux/phy.h
> @@ -298,6 +298,14 @@ struct mii_bus {
> /* RESET GPIO descriptor pointer */
> struct gpio_desc *reset_gpiod;
>
> + /* bus capabilities, used for probing */
> + enum {
> + MDIOBUS_NO_CAP = 0,
> + MDIOBUS_C22,
> + MDIOBUS_C45,
> + MDIOBUS_C22_C45,
> + } probe_capabilities;
> +
> /* protect access to the shared element */
> struct mutex shared_lock;
>
> --
> 2.17.1
