Re: [PATCH net] net: stmmac: Fix lack of link transition for fixed PHYs

From: Florian Fainelli <f.fainelli@gmail.com>
Date: Sun, 13 Nov 2016 17:50:35 -0800

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")

I added the missing "Fixes: " here.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

Applied and queued up for -stable, thanks Florian.