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%3Ba=su...
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 stable@vger.kernel.org know about it.
From 6aae7a6232c6444941de8e5a1e0cc42442ab9bce Mon Sep 17 00:00:00 2001
From: Russell King rmk+kernel@armlinux.org.uk Date: Tue, 12 Dec 2017 10:45:36 +0000 Subject: [PATCH] net: phy: fix resume handling
From: Russell King rmk+kernel@armlinux.org.uk
[ 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 rmk+kernel@armlinux.org.uk Reviewed-by: Andrew Lunn andrew@lunn.ch Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@verizon.com 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