@@ -329,6 +329,44 @@ void phy_resolve_aneg_linkmode(struct phy_device *phydev)
}
EXPORT_SYMBOL_GPL(phy_resolve_aneg_linkmode);
+/**
+ * phy_check_downshift - check whether downshift occurred
+ * @phydev: The phy_device struct
+ *
+ * Check whether a downshift to a lower speed occurred. If this should be the
+ * case warn the user.
+ * Prerequisite for detecting downshift is that PHY driver implements the
+ * read_status callback and sets phydev->speed to the actual link speed.
+ */
+void phy_check_downshift(struct phy_device *phydev)
+{
+ __ETHTOOL_DECLARE_LINK_MODE_MASK(common);
+ int i, speed = SPEED_UNKNOWN;
+
+ phydev->downshifted_rate = 0;
+
+ if (phydev->autoneg == AUTONEG_DISABLE ||
+ phydev->speed == SPEED_UNKNOWN)
+ return;
+
+ linkmode_and(common, phydev->lp_advertising, phydev->advertising);
+
+ for (i = 0; i < ARRAY_SIZE(settings); i++)
+ if (test_bit(settings[i].bit, common)) {
+ speed = settings[i].speed;
+ break;
+ }
+
+ if (speed == SPEED_UNKNOWN || phydev->speed >= speed)
+ return;
+
+ phydev_warn(phydev, "Downshift occurred from negotiated speed %s to actual speed %s, check cabling!\n",
+ phy_speed_to_str(speed), phy_speed_to_str(phydev->speed));
+
+ phydev->downshifted_rate = 1;
+}
+EXPORT_SYMBOL_GPL(phy_check_downshift);
+
static int phy_resolve_min_speed(struct phy_device *phydev, bool fdx_only)
{
__ETHTOOL_DECLARE_LINK_MODE_MASK(common);
@@ -96,9 +96,10 @@ void phy_print_status(struct phy_device *phydev)
{
if (phydev->link) {
netdev_info(phydev->attached_dev,
- "Link is Up - %s/%s - flow control %s\n",
+ "Link is Up - %s/%s %s- flow control %s\n",
phy_speed_to_str(phydev->speed),
phy_duplex_to_str(phydev->duplex),
+ phydev->downshifted_rate ? "(downshifted) " : "",
phy_pause_str(phydev));
} else {
netdev_info(phydev->attached_dev, "Link is Down\n");
@@ -507,6 +508,7 @@ static int phy_check_link_status(struct phy_device *phydev)
return err;
if (phydev->link && phydev->state != PHY_RUNNING) {
+ phy_check_downshift(phydev);
phydev->state = PHY_RUNNING;
phy_link_up(phydev);
} else if (!phydev->link && phydev->state != PHY_NOLINK) {
@@ -365,6 +365,7 @@ struct macsec_ops;
* suspended_by_mdio_bus: Set to true if this phy was suspended by MDIO bus.
* sysfs_links: Internal boolean tracking sysfs symbolic links setup/removal.
* loopback_enabled: Set true if this phy has been loopbacked successfully.
+ * downshifted_rate: Set true if link speed has been downshifted.
* state: state of the PHY for management purposes
* dev_flags: Device-specific flags used by the PHY driver.
* irq: IRQ number of the PHY's interrupt (-1 if none)
@@ -405,6 +406,7 @@ struct phy_device {
unsigned suspended_by_mdio_bus:1;
unsigned sysfs_links:1;
unsigned loopback_enabled:1;
+ unsigned downshifted_rate:1;
unsigned autoneg:1;
/* The most recently read link state */
@@ -698,6 +700,7 @@ static inline bool phy_is_started(struct phy_device *phydev)
void phy_resolve_aneg_pause(struct phy_device *phydev);
void phy_resolve_aneg_linkmode(struct phy_device *phydev);
+void phy_check_downshift(struct phy_device *phydev);
/**
* phy_read - Convenience function for reading a given PHY register
So far PHY drivers have to check whether a downshift occurred to be able to notify the user. To make life of drivers authors a little bit easier move the downshift notification to phylib. phy_check_downshift() compares the highest mutually advertised speed with the actual value of phydev->speed (typically read by the PHY driver from a vendor-specific register) to detect a downshift. v2: - Add downshift hint to phy_print_status Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> --- drivers/net/phy/phy-core.c | 38 ++++++++++++++++++++++++++++++++++++++ drivers/net/phy/phy.c | 4 +++- include/linux/phy.h | 3 +++ 3 files changed, 44 insertions(+), 1 deletion(-)