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Message-ID: <CAGm1_ku63P+xT8RKCeGJdmv065dA03p_kzdJQhrvAxUjJc2oSg@mail.gmail.com>
Date: Mon, 28 Nov 2016 11:28:04 +0100
From: Yegor Yefremov <yegorslists@...glemail.com>
To: Jerome Brunet <jbrunet@...libre.com>
Cc: netdev <netdev@...r.kernel.org>, devicetree@...r.kernel.org,
Florian Fainelli <f.fainelli@...il.com>,
Carlo Caione <carlo@...one.org>,
Kevin Hilman <khilman@...libre.com>,
Giuseppe Cavallaro <peppe.cavallaro@...com>,
Alexandre TORGUE <alexandre.torgue@...com>,
Martin Blumenstingl <martin.blumenstingl@...glemail.com>,
Andre Roth <neolynx@...il.com>, Andrew Lunn <andrew@...n.ch>,
Neil Armstrong <narmstrong@...libre.com>,
linux-amlogic@...ts.infradead.org,
linux-arm-kernel <linux-arm-kernel@...ts.infradead.org>,
kernel list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH net-next v3 1/4] net: phy: add an option to disable EEE advertisement
On Mon, Nov 28, 2016 at 10:46 AM, Jerome Brunet <jbrunet@...libre.com> wrote:
> This patch adds an option to disable EEE advertisement in the generic PHY
> by providing a mask of prohibited modes corresponding to the value found in
> the MDIO_AN_EEE_ADV register.
>
> On some platforms, PHY Low power idle seems to be causing issues, even
> breaking the link some cases. The patch provides a convenient way for these
> platforms to disable EEE advertisement and work around the issue.
>
> Signed-off-by: Jerome Brunet <jbrunet@...libre.com>
Tested using Baltos ir2110 device (cpsw + at8035 PHY).
Tested-by: Yegor Yefremov <yegorslists@...glemail.com>
> ---
> drivers/net/phy/phy.c | 3 ++
> drivers/net/phy/phy_device.c | 80 +++++++++++++++++++++++++++++++++++++++-----
> include/linux/phy.h | 3 ++
> 3 files changed, 77 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
> index 73adbaa9ac86..a3981cc6448a 100644
> --- a/drivers/net/phy/phy.c
> +++ b/drivers/net/phy/phy.c
> @@ -1396,6 +1396,9 @@ int phy_ethtool_set_eee(struct phy_device *phydev, struct ethtool_eee *data)
> {
> int val = ethtool_adv_to_mmd_eee_adv_t(data->advertised);
>
> + /* Mask prohibited EEE modes */
> + val &= ~phydev->eee_broken_modes;
> +
> phy_write_mmd_indirect(phydev, MDIO_AN_EEE_ADV, MDIO_MMD_AN, val);
>
> return 0;
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index ba86c191a13e..83e52f1b80f2 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -1121,6 +1121,43 @@ static int genphy_config_advert(struct phy_device *phydev)
> }
>
> /**
> + * genphy_config_eee_advert - disable unwanted eee mode advertisement
> + * @phydev: target phy_device struct
> + *
> + * Description: Writes MDIO_AN_EEE_ADV after disabling unsupported energy
> + * efficent ethernet modes. Returns 0 if the PHY's advertisement hasn't
> + * changed, and 1 if it has changed.
> + */
> +static int genphy_config_eee_advert(struct phy_device *phydev)
> +{
> + u32 broken = phydev->eee_broken_modes;
> + u32 old_adv, adv;
> +
> + /* Nothing to disable */
> + if (!broken)
> + return 0;
> +
> + /* If the following call fails, we assume that EEE is not
> + * supported by the phy. If we read 0, EEE is not advertised
> + * In both case, we don't need to continue
> + */
> + adv = phy_read_mmd_indirect(phydev, MDIO_AN_EEE_ADV, MDIO_MMD_AN);
> + if (adv <= 0)
> + return 0;
> +
> + old_adv = adv;
> + adv &= ~broken;
> +
> + /* Advertising remains unchanged with the broken mask */
> + if (old_adv == adv)
> + return 0;
> +
> + phy_write_mmd_indirect(phydev, MDIO_AN_EEE_ADV, MDIO_MMD_AN, adv);
> +
> + return 1;
> +}
> +
> +/**
> * genphy_setup_forced - configures/forces speed/duplex from @phydev
> * @phydev: target phy_device struct
> *
> @@ -1178,15 +1215,20 @@ EXPORT_SYMBOL(genphy_restart_aneg);
> */
> int genphy_config_aneg(struct phy_device *phydev)
> {
> - int result;
> + int err, changed;
> +
> + changed = genphy_config_eee_advert(phydev);
>
> if (AUTONEG_ENABLE != phydev->autoneg)
> return genphy_setup_forced(phydev);
>
> - result = genphy_config_advert(phydev);
> - if (result < 0) /* error */
> - return result;
> - if (result == 0) {
> + err = genphy_config_advert(phydev);
> + if (err < 0) /* error */
> + return err;
> +
> + changed |= err;
> +
> + if (changed == 0) {
> /* Advertisement hasn't changed, but maybe aneg was never on to
> * begin with? Or maybe phy was isolated?
> */
> @@ -1196,16 +1238,16 @@ int genphy_config_aneg(struct phy_device *phydev)
> return ctl;
>
> if (!(ctl & BMCR_ANENABLE) || (ctl & BMCR_ISOLATE))
> - result = 1; /* do restart aneg */
> + changed = 1; /* do restart aneg */
> }
>
> /* Only restart aneg if we are advertising something different
> * than we were before.
> */
> - if (result > 0)
> - result = genphy_restart_aneg(phydev);
> + if (changed > 0)
> + return genphy_restart_aneg(phydev);
>
> - return result;
> + return 0;
> }
> EXPORT_SYMBOL(genphy_config_aneg);
>
> @@ -1563,6 +1605,21 @@ static void of_set_phy_supported(struct phy_device *phydev)
> __set_phy_supported(phydev, max_speed);
> }
>
> +static void of_set_phy_eee_broken(struct phy_device *phydev)
> +{
> + struct device_node *node = phydev->mdio.dev.of_node;
> + u32 broken;
> +
> + if (!IS_ENABLED(CONFIG_OF_MDIO))
> + return;
> +
> + if (!node)
> + return;
> +
> + if (!of_property_read_u32(node, "eee-broken-modes", &broken))
> + phydev->eee_broken_modes = broken;
> +}
> +
> /**
> * phy_probe - probe and init a PHY device
> * @dev: device to probe and init
> @@ -1600,6 +1657,11 @@ static int phy_probe(struct device *dev)
> of_set_phy_supported(phydev);
> phydev->advertising = phydev->supported;
>
> + /* Get the EEE modes we want to prohibit. We will ask
> + * the PHY stop advertising these mode later on
> + */
> + of_set_phy_eee_broken(phydev);
> +
> /* Set the state to READY by default */
> phydev->state = PHY_READY;
>
> diff --git a/include/linux/phy.h b/include/linux/phy.h
> index edde28ce163a..b53177fd38af 100644
> --- a/include/linux/phy.h
> +++ b/include/linux/phy.h
> @@ -417,6 +417,9 @@ struct phy_device {
> u32 advertising;
> u32 lp_advertising;
>
> + /* Energy efficient ethernet modes which should be prohibited */
> + u32 eee_broken_modes;
> +
> int autoneg;
>
> int link_timeout;
> --
> 2.7.4
>
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