Re: [PATCH net] net: stmmac: Fix lack of link transition for fixed PHYs
From: Giuseppe CAVALLARO <hidden>
Date: 2016-11-14 07:42:55
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On 11/14/2016 2:50 AM, Florian Fainelli wrote:
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.fainelli@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.Acked-by: Giuseppe Cavallaro <redacted>
quoted hunk ↗ jump to hunk
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);