Commit 52f95bbfcf72 ("stmmac: fix adjust link call in case of a switch is attached") added some logic to avoid polling the fixed PHY and therefore invoking the adjust_link callback more than once, since this is a fixed PHY and link events won't be generated.
This works fine the first time, because we start with phydev->irq = PHY_POLL, so we call adjust_link, then we set phydev->irq = PHY_IGNORE_INTERRUPT and we stop polling the PHY. Now, if we called ndo_close(), which calls both phy_stop() and does an explicit netif_carrier_off(), we end up with a link down. Upon calling ndo_open() again, despite starting the PHY state machine, we have PHY_IGNORE_INTERRUPT set, and we generate no link event at all, so the link is permanently down. 52f95bbfcf72 ("stmmac: fix adjust link call in case of a switch is attached") Signed-off-by: Florian Fainelli <f.faine...@gmail.com> --- Alexandre, Peppe, The original patch is already a hack, but since this is a bugfix, I took the same approach that you did here to backport this to -stable kernels. drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 10909c9c0033..03dbf8e89c4c 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -882,6 +882,13 @@ static int stmmac_init_phy(struct net_device *dev) return -ENODEV; } + /* stmmac_adjust_link will change this to PHY_IGNORE_INTERRUPT to avoid + * subsequent PHY polling, make sure we force a link transition if + * we have a UP/DOWN/UP transition + */ + if (phydev->is_pseudo_fixed_link) + phydev->irq = PHY_POLL; + pr_debug("stmmac_init_phy: %s: attached to PHY (UID 0x%x)" " Link = %d\n", dev->name, phydev->phy_id, phydev->link); -- 2.9.3