On Thu, Oct 10, 2019 at 09:46:21PM +0200, Marek Vasut wrote: > The KSZ8051 PHY and the KSZ8794/KSZ8795/KSZ8765 switch share exactly the > same PHY ID. Since KSZ8051 is higher in the ksphy_driver[] list of PHYs > in the micrel PHY driver, it is used even with the KSZ87xx switch. This > is wrong, since the KSZ8051 configures registers of the PHY which are > not present on the simplified KSZ87xx switch PHYs and misconfigures > other registers of the KSZ87xx switch PHYs. > > Fortunatelly, it is possible to tell apart the KSZ8051 PHY from the > KSZ87xx switch by checking the Basic Status register Bit 0, which is > read-only and indicates presence of the Extended Capability Registers. > The KSZ8051 PHY has those registers while the KSZ87xx switch does not. > > This patch implements simple check for the presence of this bit for > both the KSZ8051 PHY and KSZ87xx switch, to let both use the correct > PHY driver instance. > > Signed-off-by: Marek Vasut <ma...@denx.de> > Cc: Andrew Lunn <and...@lunn.ch> > Cc: David S. Miller <da...@davemloft.net> > Cc: Florian Fainelli <f.faine...@gmail.com> > Cc: George McCollister <george.mccollis...@gmail.com> > Cc: Heiner Kallweit <hkallwe...@gmail.com> > Cc: Tristram Ha <tristram...@microchip.com> > Cc: Woojung Huh <woojung....@microchip.com> > --- > NOTE: It was also suggested to populate phydev->dev_flags to discern > the PHY from the switch, this does not work for setups where > the switch is used as a PHY without a DSA driver. Checking the > BMSR Bit 0 for Extended Capability Register works for both DSA > and non-DSA usecase. > V2: Move phy_id check into ksz8051_match_phy_device() and > ksz8795_match_phy_device() and drop phy_id{,_mask} from the > ksphy_driver[] list to avoid matching on other PHY IDs. > --- > drivers/net/phy/micrel.c | 40 ++++++++++++++++++++++++++++++++++++---- > 1 file changed, 36 insertions(+), 4 deletions(-) > > diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c > index 2fea5541c35a..028a4a177790 100644 > --- a/drivers/net/phy/micrel.c > +++ b/drivers/net/phy/micrel.c > @@ -341,6 +341,25 @@ static int ksz8041_config_aneg(struct phy_device *phydev) > return genphy_config_aneg(phydev); > } > > +static int ksz8051_match_phy_device(struct phy_device *phydev) > +{ > + int ret; > + > + if ((phydev->phy_id & MICREL_PHY_ID_MASK) != PHY_ID_KSZ8051) > + return 0; > + > + ret = phy_read(phydev, MII_BMSR); > + if (ret < 0) > + return ret; > + > + /* KSZ8051 PHY and KSZ8794/KSZ8795/KSZ8765 switch share the same > + * exact PHY ID. However, they can be told apart by the extended > + * capability registers presence. The KSZ8051 PHY has them while > + * the switch does not. > + */ > + return ret & BMSR_ERCAP; > +} > + > static int ksz8081_config_init(struct phy_device *phydev) > { > /* KSZPHY_OMSO_FACTORY_TEST is set at de-assertion of the reset line > @@ -364,6 +383,21 @@ static int ksz8061_config_init(struct phy_device *phydev) > return kszphy_config_init(phydev); > } > > +static int ksz8795_match_phy_device(struct phy_device *phydev) > +{ > + int ret; > + > + if ((phydev->phy_id & MICREL_PHY_ID_MASK) != PHY_ID_KSZ8795) > + return 0; > + > + ret = phy_read(phydev, MII_BMSR); > + if (ret < 0) > + return ret; > + > + /* See comment in ksz8051_match_phy_device() for details. */ > + return !(ret & BMSR_ERCAP); > +} > +
Hi Marek, given the similarity between ksz8051_match_phy_device() and ksz8795_match_phy_device() I wonder if a common helper is appropriate. > static int ksz9021_load_values_from_of(struct phy_device *phydev, > const struct device_node *of_node, > u16 reg, > @@ -1017,8 +1051,6 @@ static struct phy_driver ksphy_driver[] = { > .suspend = genphy_suspend, > .resume = genphy_resume, > }, { > - .phy_id = PHY_ID_KSZ8051, > - .phy_id_mask = MICREL_PHY_ID_MASK, > .name = "Micrel KSZ8051", > /* PHY_BASIC_FEATURES */ > .driver_data = &ksz8051_type, > @@ -1029,6 +1061,7 @@ static struct phy_driver ksphy_driver[] = { > .get_sset_count = kszphy_get_sset_count, > .get_strings = kszphy_get_strings, > .get_stats = kszphy_get_stats, > + .match_phy_device = ksz8051_match_phy_device, > .suspend = genphy_suspend, > .resume = genphy_resume, > }, { > @@ -1141,13 +1174,12 @@ static struct phy_driver ksphy_driver[] = { > .suspend = genphy_suspend, > .resume = genphy_resume, > }, { > - .phy_id = PHY_ID_KSZ8795, > - .phy_id_mask = MICREL_PHY_ID_MASK, > .name = "Micrel KSZ8795", > /* PHY_BASIC_FEATURES */ > .config_init = kszphy_config_init, > .config_aneg = ksz8873mll_config_aneg, > .read_status = ksz8873mll_read_status, > + .match_phy_device = ksz8795_match_phy_device, > .suspend = genphy_suspend, > .resume = genphy_resume, > }, { > -- > 2.23.0 >