From c01cb483cfabeae6ec26d99edf07b4b80d3f309b Mon Sep 17 00:00:00 2001
From: "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>
Date: Tue, 23 Nov 2021 16:44:02 +0100
Subject: [PATCH 01/37] net: phylink: Force link down and retrigger resolve on
interface change
Git-commit: 80662f4fd4771bc9c7cc4abdfbe866ebd1179621
Patch-mainline: v5.16-rc3
References: git-fixes
On PHY state change the phylink_resolve() function can read stale
information from the MAC and report incorrect link speed and duplex to
the kernel message log.
Example with a Marvell 88X3310 PHY connected to a SerDes port on Marvell
88E6393X switch:
- PHY driver triggers state change due to PHY interface mode being
changed from 10gbase-r to 2500base-x due to copper change in speed
from 10Gbps to 2.5Gbps, but the PHY itself either hasn't yet changed
its interface to the host, or the interrupt about loss of SerDes link
hadn't arrived yet (there can be a delay of several milliseconds for
this), so we still think that the 10gbase-r mode is up
- phylink_resolve()
- phylink_mac_pcs_get_state()
- this fills in speed=10g link=up
- interface mode is updated to 2500base-x but speed is left at 10Gbps
- phylink_major_config()
- interface is changed to 2500base-x
- phylink_link_up()
- mv88e6xxx_mac_link_up()
- .port_set_speed_duplex()
- speed is set to 10Gbps
- reports "Link is Up - 10Gbps/Full" to dmesg
Afterwards when the interrupt finally arrives for mv88e6xxx, another
resolve is forced in which we get the correct speed from
phylink_mac_pcs_get_state(), but since the interface is not being
changed anymore, we don't call phylink_major_config() but only
phylink_mac_config(), which does not set speed/duplex anymore.
To fix this, we need to force the link down and trigger another resolve
on PHY interface change event.
Fixes: 9525ae83959b ("phylink: add phylink infrastructure")
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Denis Kirjanov <denis.kirjanov@suse.com>
---
drivers/net/phy/phylink.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index d18e4e76a5df..9dba77cecbfc 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -657,6 +657,7 @@ static void phylink_resolve(struct work_struct *w)
struct phylink_link_state link_state;
struct net_device *ndev = pl->netdev;
bool mac_config = false;
+ bool retrigger = false;
bool cur_link_state;
mutex_lock(&pl->state_mutex);
@@ -670,6 +671,7 @@ static void phylink_resolve(struct work_struct *w)
link_state.link = false;
} else if (pl->mac_link_dropped) {
link_state.link = false;
+ retrigger = true;
} else {
switch (pl->cur_link_an_mode) {
case MLO_AN_PHY:
@@ -694,6 +696,15 @@ static void phylink_resolve(struct work_struct *w)
/* Only update if the PHY link is up */
if (pl->phydev && pl->phy_state.link) {
+ /* If the interface has changed, force a
+ * link down event if the link isn't already
+ * down, and re-resolve.
+ */
+ if (link_state.interface !=
+ pl->phy_state.interface) {
+ retrigger = true;
+ link_state.link = false;
+ }
link_state.interface = pl->phy_state.interface;
/* If we have a PHY, we need to update with
@@ -736,7 +747,7 @@ static void phylink_resolve(struct work_struct *w)
else
phylink_link_up(pl, link_state);
}
- if (!link_state.link && pl->mac_link_dropped) {
+ if (!link_state.link && retrigger) {
pl->mac_link_dropped = false;
queue_work(system_power_efficient_wq, &pl->resolve);
}
--
2.16.4