[PATCH 5.4 13/53] lan743x: fix deadlock in lan743x_phy_link_status_change()

Greg Kroah-Hartman
2022-02-28T17:34:58Z

From: Heiner Kallweit <hkallweit1@gmail.com>

commit ddb826c2c92d461f290a7bab89e7c28696191875 upstream.

Usage of phy_ethtool_get_link_ksettings() in the link status change
handler isn't needed, and in combination with the referenced change
it results in a deadlock. Simply remove the call and replace it with
direct access to phydev->speed. The duplex argument of
lan743x_phy_update_flowcontrol() isn't used and can be removed.

Fixes: c10a485c3de5 ("phy: phy_ethtool_ksettings_get: Lock the phy for consistency")
Reported-by: Alessandro B Maurici <abmaurici@gmail.com>
Tested-by: Alessandro B Maurici <abmaurici@gmail.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/40e27f76-0ba3-dcef-ee32-a78b9df38b0f@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[dannf: adjust context]
Signed-off-by: dann frazier <dann.frazier@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

---
drivers/net/ethernet/microchip/lan743x_main.c | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)

--- a/drivers/net/ethernet/microchip/lan743x_main.c
+++ b/drivers/net/ethernet/microchip/lan743x_main.c
@@ -916,8 +916,7 @@ static int lan743x_phy_reset(struct lan7
}

static void lan743x_phy_update_flowcontrol(struct lan743x_adapter *adapter,
- u8 duplex, u16 local_adv,
- u16 remote_adv)
+ u16 local_adv, u16 remote_adv)
{
struct lan743x_phy *phy = &adapter->phy;
u8 cap;
@@ -944,22 +943,17 @@ static void lan743x_phy_link_status_chan

phy_print_status(phydev);
if (phydev->state == PHY_RUNNING) {
- struct ethtool_link_ksettings ksettings;
int remote_advertisement = 0;
int local_advertisement = 0;

- memset(&ksettings, 0, sizeof(ksettings));
- phy_ethtool_get_link_ksettings(netdev, &ksettings);
local_advertisement =
linkmode_adv_to_mii_adv_t(phydev->advertising);
remote_advertisement =
linkmode_adv_to_mii_adv_t(phydev->lp_advertising);

- lan743x_phy_update_flowcontrol(adapter,
- ksettings.base.duplex,
- local_advertisement,
+ lan743x_phy_update_flowcontrol(adapter, local_advertisement,
remote_advertisement);
- lan743x_ptp_update_latency(adapter, ksettings.base.speed);
+ lan743x_ptp_update_latency(adapter, phydev->speed);
}
}