diff mbox series

PHY: Fix no autoneg corner case

Message ID m3plmhhx6d.fsf@t19.piap.pl (mailing list archive)
State New
Headers show
Series PHY: Fix no autoneg corner case | expand

Commit Message

Krzysztof Hałasa Nov. 27, 2024, 8:56 a.m. UTC
phydev->autoneg appears to indicate if autonegotiation is enabled or
not. Unfortunately it's initially set based on the supported capability
rather than the actual hw setting. While in most cases there is no
difference (i.e., autoneg is supported and on by default), certain
adapters (e.g. fiber optics) use fixed settings, configured in hardware.

Now autoneg flag is set only when it's supported and actually used.

Signed-off-by: Krzysztof Hałasa <khalasa@piap.pl>

Comments

Andrew Lunn Nov. 27, 2024, 5:37 p.m. UTC | #1
On Wed, Nov 27, 2024 at 09:56:42AM +0100, Krzysztof Hałasa wrote:
> phydev->autoneg appears to indicate if autonegotiation is enabled or
> not.

Correct.

> Unfortunately it's initially set based on the supported capability
> rather than the actual hw setting.

We need a clear definition of 'initially', and when does it actually
matter.

Initially, things like speed, duplex and set to UNKNOWN. They don't
make any sense until the link is up. phydev->advertise is set to
phydev->supported, so that we advertise all the capabilities of the
PHY. However, at probe, this does not really matter, it is only when
phy_start() is called is the hardware actually configured with what it
should advertise, or even if it should do auto-neg or not.

In the end, this might not matter.

> While in most cases there is no
> difference (i.e., autoneg is supported and on by default), certain
> adapters (e.g. fiber optics) use fixed settings, configured in hardware.

If the hardware is not capable of supporting autoneg, why is autoneg
in phydev->supported? To me, that is the real issue here.

	Andrew
diff mbox series

Patch

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 366cf3b2cbb0..6858f512558b 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -3453,7 +3453,7 @@  static int phy_probe(struct device *dev)
 	struct phy_device *phydev = to_phy_device(dev);
 	struct device_driver *drv = phydev->mdio.dev.driver;
 	struct phy_driver *phydrv = to_phy_driver(drv);
-	int err = 0;
+	int err = 0, bmcr;
 
 	phydev->drv = phydrv;
 
@@ -3495,8 +3495,12 @@  static int phy_probe(struct device *dev)
 	if (err)
 		goto out;
 
+	err = bmcr = phy_read(phydev, MII_BMCR);
+	if (err < 0)
+		goto out;
+
 	if (!linkmode_test_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
-			       phydev->supported))
+			       phydev->supported) || !(bmcr & BMCR_ANENABLE))
 		phydev->autoneg = 0;
 
 	if (linkmode_test_bit(ETHTOOL_LINK_MODE_1000baseT_Half_BIT,