From: Vladimir Oltean <vladimir.olt...@nxp.com>
Currently Linux has no control over whether a MAC-to-PHY interface uses
in-band signaling or not, even though phylink has the
managed = "in-band-status";
property which denotes that the MAC expects in-band signaling to be used.
The problem is really that if the in-band signaling is configurable in
both the PHY and the MAC, there is a risk that they are out of sync
unless phylink manages them both. Most if not all in-band autoneg state
machines follow IEEE 802.3 clause 37, which means that they will not
change the operating mode of the SERDES lane from control to data mode
unless in-band AN completed successfully. Therefore traffic will not
work.
It is particularly unpleasant that currently, we assume that PHYs which
have configurable in-band AN come pre-configured from a prior boot stage
such as U-Boot, because once the bootloader changes, all bets are off.
Let's introduce a new PHY driver method for configuring in-band autoneg,
and make phylink be its first user. The main PHY library does not call
phy_config_inband_autoneg, because it does not know what to configure it
to. Presumably, non-phylink drivers can also call phy_config_inband_autoneg
individually.
Signed-off-by: Vladimir Oltean <vladimir.olt...@nxp.com>
---
drivers/net/phy/phy.c | 12 ++++++++++++
drivers/net/phy/phylink.c | 8 ++++++++
include/linux/phy.h | 8 ++++++++
3 files changed, 28 insertions(+)
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index fdb914b5b857..d6c63c54943e 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -748,6 +748,18 @@ static int phy_check_link_status(struct phy_device *phydev)
return 0;
}
+int phy_config_inband_aneg(struct phy_device *phydev, bool enabled)
+{
+ if (!phydev->drv)
+ return -EIO;
+
+ if (!phydev->drv->config_inband_aneg)
+ return -EOPNOTSUPP;
+
+ return phydev->drv->config_inband_aneg(phydev, enabled);
+}
+EXPORT_SYMBOL(phy_config_inband_aneg);
+
/**
* phy_start_aneg - start auto-negotiation for this PHY device
* @phydev: the phy_device struct
diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 84f6e197f965..ef3e947d5019 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -978,6 +978,14 @@ static int phylink_bringup_phy(struct phylink *pl, struct
phy_device *phy,
return ret;
}
+ ret = phy_config_inband_aneg(phy,
+ (pl->cur_link_an_mode == MLO_AN_INBAND));
+ if (ret && ret != -EOPNOTSUPP) {
+ phylink_warn(pl, "failed to configure PHY in-band autoneg:
%d\n",
+ ret);
+ return ret;
+ }
+
phy->phylink = pl;
phy->phy_link_change = phylink_phy_change;
diff --git a/include/linux/phy.h b/include/linux/phy.h
index c130788306c8..2260b512ffbf 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -746,6 +746,13 @@ struct phy_driver {
*/
int (*config_aneg)(struct phy_device *phydev);
+ /**
+ * @config_inband_aneg: Enable or disable in-band auto-negotiation for
+ * the system-side interface if the PHY operates in a mode that
+ * requires it: (Q)SGMII, USXGMII, 1000Base-X, etc.
+ */
+ int (*config_inband_aneg)(struct phy_device *phydev, bool enabled);
+
/** @aneg_done: Determines the auto negotiation result */
int (*aneg_done)(struct phy_device *phydev);
@@ -1394,6 +1401,7 @@ void phy_detach(struct phy_device *phydev);
void phy_start(struct phy_device *phydev);
void phy_stop(struct phy_device *phydev);
int phy_start_aneg(struct phy_device *phydev);
+int phy_config_inband_aneg(struct phy_device *phydev, bool enabled);
int phy_aneg_done(struct phy_device *phydev);
int phy_speed_down(struct phy_device *phydev, bool sync);
int phy_speed_up(struct phy_device *phydev);
--
2.25.1
