net: phy: improve phy state checking

Add helpers phy_is_started() and __phy_is_started() to avoid open-coded
checks whether PHY has been started. To make the check easier move
PHY_HALTED before PHY_UP in enum phy_state. Further improvements:

phy_start_aneg():
Return -EBUSY and print warning if function is called from a non-started
state (DOWN, READY, HALTED). Better check because function is exported
and drivers may use it incorrectly.

phy_interrupt():
Return IRQ_NONE also if state is DOWN or READY. We should never receive
an interrupt in one of these states, but better play safe.

phy_stop():
Just return and print a warning if PHY is in a non-started state.
This warning should help to identify drivers with unbalanced calls to
phy_start() / phy_stop().

phy_state_machine():
Schedule state machine run only if PHY is in a started state.
E.g. if state is READY we don't need the state machine, it will be
started by phy_start().

v2:
- don't use __func__ within phy_warn_state
v3:
- use WARN() instead of printing error message to facilitate debugging

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index e24708f1fc16238091acb8081889bdbd2743ae2c..21df28b9882c73ebd7cc765598641031f2d571bb 100644 (file)
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -543,6 +543,13 @@ int phy_start_aneg(struct phy_device *phydev)
 
        mutex_lock(&phydev->lock);
 
+       if (!__phy_is_started(phydev)) {
+               WARN(1, "called from state %s\n",
+                    phy_state_to_str(phydev->state));
+               err = -EBUSY;
+               goto out_unlock;
+       }
+
        if (AUTONEG_DISABLE == phydev->autoneg)
                phy_sanitize_settings(phydev);
 
@@ -553,13 +560,11 @@ int phy_start_aneg(struct phy_device *phydev)
        if (err < 0)
                goto out_unlock;
 
-       if (phydev->state != PHY_HALTED) {
-               if (AUTONEG_ENABLE == phydev->autoneg) {
-                       err = phy_check_link_status(phydev);
-               } else {
-                       phydev->state = PHY_FORCING;
-                       phydev->link_timeout = PHY_FORCE_TIMEOUT;
-               }
+       if (phydev->autoneg == AUTONEG_ENABLE) {
+               err = phy_check_link_status(phydev);
+       } else {
+               phydev->state = PHY_FORCING;
+               phydev->link_timeout = PHY_FORCE_TIMEOUT;
        }
 
 out_unlock:
@@ -709,7 +714,7 @@ void phy_stop_machine(struct phy_device *phydev)
        cancel_delayed_work_sync(&phydev->state_queue);
 
        mutex_lock(&phydev->lock);
-       if (phydev->state > PHY_UP && phydev->state != PHY_HALTED)
+       if (__phy_is_started(phydev))
                phydev->state = PHY_UP;
        mutex_unlock(&phydev->lock);
 }
@@ -760,7 +765,7 @@ static irqreturn_t phy_interrupt(int irq, void *phy_dat)
 {
        struct phy_device *phydev = phy_dat;
 
-       if (PHY_HALTED == phydev->state)
+       if (!phy_is_started(phydev))
                return IRQ_NONE;                /* It can't be ours.  */
 
        if (phydev->drv->did_interrupt && !phydev->drv->did_interrupt(phydev))
@@ -842,15 +847,18 @@ void phy_stop(struct phy_device *phydev)
 {
        mutex_lock(&phydev->lock);
 
-       if (PHY_HALTED == phydev->state)
-               goto out_unlock;
+       if (!__phy_is_started(phydev)) {
+               WARN(1, "called from state %s\n",
+                    phy_state_to_str(phydev->state));
+               mutex_unlock(&phydev->lock);
+               return;
+       }
 
        if (phy_interrupt_is_valid(phydev))
                phy_disable_interrupts(phydev);
 
        phydev->state = PHY_HALTED;
 
-out_unlock:
        mutex_unlock(&phydev->lock);
 
        phy_state_machine(&phydev->state_queue.work);
@@ -984,7 +992,7 @@ void phy_state_machine(struct work_struct *work)
         * state machine would be pointless and possibly error prone when
         * called from phy_disconnect() synchronously.
         */
-       if (phy_polling_mode(phydev) && old_state != PHY_HALTED)
+       if (phy_polling_mode(phydev) && phy_is_started(phydev))
                phy_queue_state_machine(phydev, PHY_STATE_TIME);
 }
 

diff --git a/include/linux/phy.h b/include/linux/phy.h
index 8f927246acdbbda6399a822ba91924dfeeee9f77..da039f211c228a8f6027a98c6c3df076b26a1842 100644 (file)
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -319,12 +319,12 @@ struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr);
 enum phy_state {
        PHY_DOWN = 0,
        PHY_READY,
+       PHY_HALTED,
        PHY_UP,
        PHY_RUNNING,
        PHY_NOLINK,
        PHY_FORCING,
        PHY_CHANGELINK,
-       PHY_HALTED,
        PHY_RESUMING
 };
 
@@ -669,6 +669,28 @@ phy_lookup_setting(int speed, int duplex, const unsigned long *mask,
 size_t phy_speeds(unsigned int *speeds, size_t size,
                  unsigned long *mask);
 
+static inline bool __phy_is_started(struct phy_device *phydev)
+{
+       WARN_ON(!mutex_is_locked(&phydev->lock));
+
+       return phydev->state >= PHY_UP;
+}
+
+/**
+ * phy_is_started - Convenience function to check whether PHY is started
+ * @phydev: The phy_device struct
+ */
+static inline bool phy_is_started(struct phy_device *phydev)
+{
+       bool started;
+
+       mutex_lock(&phydev->lock);
+       started = __phy_is_started(phydev);
+       mutex_unlock(&phydev->lock);
+
+       return started;
+}
+
 void phy_resolve_aneg_linkmode(struct phy_device *phydev);
 
 /**