[PATCH RFC] phylib EEE updates

[PATCH RFC] phylib EEE updates

[Russell King - ARM Linux]

Florian,

This series of patches depends on the previous set of changes, and is
therefore net-next material.

While testing the EEE code, I discovered a number of issues:

1. It is possible to enable advertisment of EEE modes which are not
   supported by the hardware.  We omit to check the supported modes
   and mask off those modes that are not supported before writing the
   EEE advertisment register.

2. We need to restart autonegotiation after a change of the EEE
   advertisment, otherwise the link partner does not see the updated
   EEE modes.

3. SGMII connected PHYs are also capable of supporting EEE.

I'm not too sure why we have the test in phylib for the interface mode,
as the list of interface modes that support EEE is likely to increase
(eg, 10G interface modes have provision to support EEE mode.)  I did
think about killing the test, but the older interface modes probably
don't support it.  Any thoughts on what to do about that - maybe the
test should be reversed to exclude those modes which definitely don't
support EEE?

 drivers/net/phy/phy.c | 29 ++++++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)
   
-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.

[PATCH RFC 1/3] net: phy: avoid setting unsupported EEE advertisments

[Russell King]

We currently allow userspace to set any EEE advertisments it desires,
whether or not the PHY supports them.  For example:

 # ethtool --set-eee eth1 advertise 0xffffffff
 # ethtool --show-eee eth1
 EEE Settings for eth1:
        EEE status: disabled
        Tx LPI: disabled
        Supported EEE link modes:  100baseT/Full
                                   1000baseT/Full
                                   10000baseT/Full
        Advertised EEE link modes:  100baseT/Full
                                    1000baseT/Full
                                    1000baseKX/Full
                                    10000baseT/Full
                                    10000baseKX4/Full
                                    10000baseKR/Full

Clearly, this is not sane, we should only allow link modes that are
supported to be advertised (as we do elsewhere.)  Ensure that we mask
the MDIO_AN_EEE_ADV value with the capabilities retrieved from the
MDIO_PCS_EEE_ABLE register.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 drivers/net/phy/phy.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index ba4676ee9018..7b1c93b0233a 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -1332,17 +1332,22 @@ EXPORT_SYMBOL(phy_ethtool_get_eee);
  */
 int phy_ethtool_set_eee(struct phy_device *phydev, struct ethtool_eee *data)
 {
-	int val = ethtool_adv_to_mmd_eee_adv_t(data->advertised);
+	int cap, adv;
 
 	if (!phydev->drv)
 		return -EIO;
 
-	/* Mask prohibited EEE modes */
-	val &= ~phydev->eee_broken_modes;
+	/* Get Supported EEE */
+	cap = phy_read_mmd(phydev, MDIO_MMD_PCS, MDIO_PCS_EEE_ABLE);
+	if (cap < 0)
+		return cap;
 
-	phy_write_mmd(phydev, MDIO_MMD_AN, MDIO_AN_EEE_ADV, val);
+	adv = ethtool_adv_to_mmd_eee_adv_t(data->advertised) & cap;
 
-	return 0;
+	/* Mask prohibited EEE modes */
+	adv &= ~phydev->eee_broken_modes;
+
+	return phy_write_mmd(phydev, MDIO_MMD_AN, MDIO_AN_EEE_ADV, adv);
 }
 EXPORT_SYMBOL(phy_ethtool_set_eee);
 
-- 
2.7.4

[PATCH RFC 2/3] net: phy: restart phy autonegotiation after EEE advertisment change

[Russell King]

When the EEE advertisment is changed, we should restart autonegotiation
to update the link partner with the new EEE settings.  Add this trigger
but only if the advertisment has changed.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 drivers/net/phy/phy.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 7b1c93b0233a..e1d41fa5caf5 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -1332,7 +1332,7 @@ EXPORT_SYMBOL(phy_ethtool_get_eee);
  */
 int phy_ethtool_set_eee(struct phy_device *phydev, struct ethtool_eee *data)
 {
-	int cap, adv;
+	int cap, old_adv, adv, ret;
 
 	if (!phydev->drv)
 		return -EIO;
@@ -1342,12 +1342,29 @@ int phy_ethtool_set_eee(struct phy_device *phydev, struct ethtool_eee *data)
 	if (cap < 0)
 		return cap;
 
+	old_adv = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_AN_EEE_ADV);
+	if (old_adv < 0)
+		return old_adv;
+
 	adv = ethtool_adv_to_mmd_eee_adv_t(data->advertised) & cap;
 
 	/* Mask prohibited EEE modes */
 	adv &= ~phydev->eee_broken_modes;
 
-	return phy_write_mmd(phydev, MDIO_MMD_AN, MDIO_AN_EEE_ADV, adv);
+	if (old_adv != adv) {
+		ret = phy_write_mmd(phydev, MDIO_MMD_AN, MDIO_AN_EEE_ADV, adv);
+		if (ret < 0)
+			return ret;
+
+		/* Restart autonegotiation so the new modes get sent to the
+		 * link partner.
+		 */
+		ret = phy_restart_aneg(phydev);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
 }
 EXPORT_SYMBOL(phy_ethtool_set_eee);
 
-- 
2.7.4

[PATCH RFC 3/3] net: phy: allow EEE with SGMII interface modes

[Russell King]

As EEE is able to work in SGMII mode as well, add it to the list of
permissable EEE modes that phy_init_eee() will accept.  This is
necessary so that EEE can work with an 88E1512 connected in SGMII mode.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 drivers/net/phy/phy.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index e1d41fa5caf5..f86cbd5e6f3f 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -1215,6 +1215,7 @@ int phy_init_eee(struct phy_device *phydev, bool clk_stop_enable)
 	if ((phydev->duplex == DUPLEX_FULL) &&
 	    ((phydev->interface == PHY_INTERFACE_MODE_MII) ||
 	    (phydev->interface == PHY_INTERFACE_MODE_GMII) ||
+	     phydev->interface == PHY_INTERFACE_MODE_SGMII ||
 	     phy_interface_is_rgmii(phydev) ||
 	     phy_is_internal(phydev))) {
 		int eee_lp, eee_cap, eee_adv;
-- 
2.7.4

Re: [PATCH RFC] phylib EEE updates

[Russell King - ARM Linux]

The 0-day builder identified some issues with the four RFC patches I
sent out before the weekend, I'll be sending v2 tomorrow.  Sorry for
the noise.

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.