Patch "[PATCH] net: phy: fix resume handling" has been added to the 4.14-stable tree
From: <gregkh@linuxfoundation.org>
Date: 2018-03-16 12:38:05
This is a note to let you know that I've just added the patch titled
[PATCH] net: phy: fix resume handling
to the 4.14-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:
net-phy-fix-resume-handling.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let [off-list ref] know about it.
From 6aae7a6232c6444941de8e5a1e0cc42442ab9bce Mon Sep 17 00:00:00 2001
From: Russell King <redacted> Date: Tue, 12 Dec 2017 10:45:36 +0000 Subject: [PATCH] net: phy: fix resume handling From: Russell King <redacted> [ Upstream commit f5e64032a799d4f54decc7eb6aafcdffb67f9ad9 ] When a PHY has the BMCR_PDOWN bit set, it may decide to ignore writes to other registers, or reset the registers to power-on defaults. Micrel PHYs do this for their interrupt registers. The current structure of phylib tries to enable interrupts before resuming (and releasing) the BMCR_PDOWN bit. This fails, causing Micrel PHYs to stop working after a suspend/resume sequence if they are using interrupts. Fix this by ensuring that the PHY driver resume methods do not take the phydev->lock mutex themselves, but the callers of phy_resume() take that lock. This then allows us to move the call to phy_resume() before we enable interrupts in phy_start(). Signed-off-by: Russell King <redacted> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <redacted> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/net/phy/at803x.c | 4 ---- drivers/net/phy/phy.c | 9 +++------ drivers/net/phy/phy_device.c | 10 ++++++---- 3 files changed, 9 insertions(+), 14 deletions(-)
--- a/drivers/net/phy/at803x.c
+++ b/drivers/net/phy/at803x.c@@ -239,14 +239,10 @@ static int at803x_resume(struct phy_devi { int value; - mutex_lock(&phydev->lock); - value = phy_read(phydev, MII_BMCR); value &= ~(BMCR_PDOWN | BMCR_ISOLATE); phy_write(phydev, MII_BMCR, value); - mutex_unlock(&phydev->lock); - return 0; } --- a/drivers/net/phy/phy.c +++ b/drivers/net/phy/phy.c
@@ -828,7 +828,6 @@ EXPORT_SYMBOL(phy_stop); */ void phy_start(struct phy_device *phydev) { - bool do_resume = false; int err = 0; mutex_lock(&phydev->lock);
@@ -841,6 +840,9 @@ void phy_start(struct phy_device *phydev phydev->state = PHY_UP; break; case PHY_HALTED: + /* if phy was suspended, bring the physical link up again */ + phy_resume(phydev); + /* make sure interrupts are re-enabled for the PHY */ if (phy_interrupt_is_valid(phydev)) { err = phy_enable_interrupts(phydev);
@@ -849,17 +851,12 @@ void phy_start(struct phy_device *phydev } phydev->state = PHY_RESUMING; - do_resume = true; break; default: break; } mutex_unlock(&phydev->lock); - /* if phy was suspended, bring the physical link up again */ - if (do_resume) - phy_resume(phydev); - phy_trigger_machine(phydev, true); } EXPORT_SYMBOL(phy_start); --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c
@@ -135,7 +135,9 @@ static int mdio_bus_phy_resume(struct de if (!mdio_bus_phy_may_suspend(phydev)) goto no_resume; + mutex_lock(&phydev->lock); ret = phy_resume(phydev); + mutex_unlock(&phydev->lock); if (ret < 0) return ret;
@@ -1026,7 +1028,9 @@ int phy_attach_direct(struct net_device if (err) goto error; + mutex_lock(&phydev->lock); phy_resume(phydev); + mutex_unlock(&phydev->lock); phy_led_triggers_register(phydev); return err;
@@ -1157,6 +1161,8 @@ int phy_resume(struct phy_device *phydev struct phy_driver *phydrv = to_phy_driver(phydev->mdio.dev.driver); int ret = 0; + WARN_ON(!mutex_is_locked(&phydev->lock)); + if (phydev->drv && phydrv->resume) ret = phydrv->resume(phydev);
@@ -1639,13 +1645,9 @@ int genphy_resume(struct phy_device *phy { int value; - mutex_lock(&phydev->lock); - value = phy_read(phydev, MII_BMCR); phy_write(phydev, MII_BMCR, value & ~BMCR_PDOWN); - mutex_unlock(&phydev->lock); - return 0; } EXPORT_SYMBOL(genphy_resume);
Patches currently in stable-queue which might be from rmk+kernel@armlinux.org.uk are queue-4.14/net-phy-fix-resume-handling.patch