| Message ID | E1eOi48-0002N2-QC@rmk-PC.armlinux.org.uk |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net] net: phy: fix resume handling | expand |
On Tue, Dec 12, 2017 at 10:45:36AM +0000, Russell King wrote: > 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> Andrew
From: Russell King <rmk+kernel@armlinux.org.uk> Date: Tue, 12 Dec 2017 10:45:36 +0000 > 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> Applied.
diff --git a/drivers/net/phy/at803x.c b/drivers/net/phy/at803x.c index 5f93e6add563..e911e4990b20 100644 --- a/drivers/net/phy/at803x.c +++ b/drivers/net/phy/at803x.c @@ -239,14 +239,10 @@ static int at803x_resume(struct phy_device *phydev) { 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; } diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c index 2b1e67bc1e73..ed10d1fc8f59 100644 --- 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 (phydev->irq != PHY_POLL) { 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); diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index 67f25ac29025..b15b31ca2618 100644 --- 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 device *dev) 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 *dev, struct phy_device *phydev, 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 *phydev) { 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);
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> --- 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(-)