This is a note to let you know that I've just added the patch titled
phy: micrel: Disable auto negotiation on startup
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
phy-micrel-disable-auto-negotiation-on-startup.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 99f81afc139c6edd14d77a91ee91685a414a1c66 Mon Sep 17 00:00:00 2001
From: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
Date: Fri, 26 Feb 2016 19:18:23 +0100
Subject: phy: micrel: Disable auto negotiation on startup
From: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>
commit 99f81afc139c6edd14d77a91ee91685a414a1c66 upstream.
Disable auto negotiation on init to properly detect an already plugged
cable at boot.
At boot, when the phy is started, it is in the PHY_UP state.
However, if a cable is plugged at boot, because auto negociation is already
enabled at the time we get the first interrupt, the phy is already running.
But the state machine then switches from PHY_UP to PHY_AN and calls
phy_start_aneg(). phy_start_aneg() will not do anything because aneg is
already enabled on the phy. It will then wait for a interrupt before going
further. This interrupt will never happen unless the cable is unplugged and
then replugged.
It was working properly before 321beec5047a (net: phy: Use interrupts when
available in NOLINK state) because switching to NOLINK meant starting
polling the phy, even if IRQ were enabled.
Fixes: 321beec5047a (net: phy: Use interrupts when available in NOLINK state)
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/phy/micrel.c | 11 +++++++++++
1 file changed, 11 insertions(+)
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -285,6 +285,17 @@ static int kszphy_config_init(struct phy
if (priv->led_mode >= 0)
kszphy_setup_led(phydev, type->led_mode_reg, priv->led_mode);
+ if (phy_interrupt_is_valid(phydev)) {
+ int ctl = phy_read(phydev, MII_BMCR);
+
+ if (ctl < 0)
+ return ctl;
+
+ ret = phy_write(phydev, MII_BMCR, ctl & ~BMCR_ANENABLE);
+ if (ret < 0)
+ return ret;
+ }
+
return 0;
}
Patches currently in stable-queue which might be from alexandre.belloni@xxxxxxxxxxx are
queue-4.4/phy-micrel-disable-auto-negotiation-on-startup.patch
