net: phy: fix resume handling
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>
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 2b1e67b..ed10d1f 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);
