On Mon, Jun 22, 2020 at 09:29:17AM +0000, Madalin Bucur (OSS) wrote: > > -----Original Message----- > > From: Calvin Johnson (OSS) <[email protected]> > > Sent: Monday, June 22, 2020 11:19 AM > > To: Jeremy Linton <[email protected]>; Russell King - ARM Linux admin > > <[email protected]>; Jon <[email protected]>; Cristi Sovaiala > > <[email protected]>; Ioana Ciornei <[email protected]>; Andrew > > Lunn <[email protected]>; Andy Shevchenko <[email protected]>; > > Florian Fainelli <[email protected]>; Madalin Bucur (OSS) > > <[email protected]> > > Cc: [email protected]; [email protected]; Calvin Johnson (OSS) > > <[email protected]> > > Subject: [net-next PATCH v2 1/3] net: phy: Allow mdio buses to auto-probe > > c45 devices > > > > From: Jeremy Linton <[email protected]> > > > > 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?
Looking further into this, I think MDIOBUS_C22 = 0, was correct. Prior to this patch, get_phy_device() was executed for C22 in this path. I'll discuss with Russell and Andrew on this and get back. > > > > > Signed-off-by: Jeremy Linton <[email protected]> > > Signed-off-by: Calvin Johnson <[email protected]> > > > > --- > > > > 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 >
