Messages in this thread | | | Date | Wed, 30 Aug 2023 12:18:13 +0200 | From | Oleksij Rempel <> | Subject | Re: [PATCH 2/2] net: phy: Provide Module 4 KSZ9477 errata (DS80000754C) |
| |
On Wed, Aug 30, 2023 at 11:21:19AM +0200, Lukasz Majewski wrote: > The KSZ9477 errata points out (in 'Module 4') the link up/down problem > when EEE (Energy Efficient Ethernet) is enabled in the device to which > the KSZ9477 tries to auto negotiate. > > The suggested workaround is to clear advertisement of EEE for PHYs in > this chip driver. > > Signed-off-by: Lukasz Majewski <lukma@denx.de> > --- > drivers/net/phy/micrel.c | 31 ++++++++++++++++++++++++++++++- > 1 file changed, 30 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c > index 87b090ad2874..469dcd8a5711 100644 > --- a/drivers/net/phy/micrel.c > +++ b/drivers/net/phy/micrel.c > @@ -1418,6 +1418,35 @@ static int ksz9131_get_features(struct phy_device *phydev) > return 0; > } > > +static int ksz9477_get_features(struct phy_device *phydev) > +{ > + __ETHTOOL_DECLARE_LINK_MODE_MASK(zero) = { 0, }; > + int ret; > + > + ret = genphy_read_abilities(phydev); > + if (ret) > + return ret; > + > + /* KSZ9477 Errata DS80000754C > + * > + * Module 4: Energy Efficient Ethernet (EEE) feature select must be > + * manually disabled > + * The EEE feature is enabled by default, but it is not fully > + * operational. It must be manually disabled through register > + * controls. If not disabled, the PHY ports can auto-negotiate > + * to enable EEE, and this feature can cause link drops when linked > + * to another device supporting EEE. > + * > + * Although, the KSZ9477 MMD register > + * (MMD_DEVICE_ID_EEE_ADV.MMD_EEE_ADV) advertise that EEE is > + * operational one needs to manualy clear them to follow the chip > + * errata. > + */ > + linkmode_and(phydev->supported_eee, phydev->supported, zero); > + > + return 0; > +} > + > #define KSZ8873MLL_GLOBAL_CONTROL_4 0x06 > #define KSZ8873MLL_GLOBAL_CONTROL_4_DUPLEX BIT(6) > #define KSZ8873MLL_GLOBAL_CONTROL_4_SPEED BIT(4) > @@ -4871,7 +4900,7 @@ static struct phy_driver ksphy_driver[] = { > .handle_interrupt = kszphy_handle_interrupt, > .suspend = genphy_suspend, > .resume = genphy_resume, > - .get_features = ksz9131_get_features, > + .get_features = ksz9477_get_features,
Sorry, i didn't described all details how to implement it.
This code will break EEE support for the KSZ8563R switch.
Please search for MICREL_KSZ8_P1_ERRATA in the kernel source. Then add new flag, for example MICREL_NO_EEE and use it in a similar way how MICREL_KSZ8_P1_ERRATA was set and used. With this implementation, first patch is not needed.
The code will be something like this: if (dev_flags & MICREL_NO_EEE) /* lots of comments */ linkmode_and(phydev->supported_eee, phydev->supported, zero); else /* lots of other comments */ linkmode_and(phydev->supported_eee, phydev->supported, PHY_EEE_CAP1_FEATURES);
On the switch driver side i would expect something like this: ksz_get_phy_flags(struct dsa_switch *ds, int port)
swtich (dev->chip_id) case KSZ8830_CHIP_ID: .... break; case KSZ9477_CHIP_ID: return MICREL_NO_EEE;
Regards, Oleksij -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
| |