diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index ca03d8e70bd1..67a768fe5b2a 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1813,13 +1813,13 @@ static int regulator_resolve_supply(struct regulator_dev *rdev) { struct regulator_dev *r; struct device *dev = rdev->dev.parent; - int ret; + int ret = 0; /* No supply to resolve? */ if (!rdev->supply_name) return 0; - /* Supply already resolved? */ + /* Supply already resolved? (fast-path without locking contention) */ if (rdev->supply) return 0; @@ -1829,7 +1829,7 @@ static int regulator_resolve_supply(struct regulator_dev *rdev) /* Did the lookup explicitly defer for us? */ if (ret == -EPROBE_DEFER) - return ret; + goto out; if (have_full_constraints()) { r = dummy_regulator_rdev; @@ -1837,15 +1837,18 @@ static int regulator_resolve_supply(struct regulator_dev *rdev) } else { dev_err(dev, "Failed to resolve %s-supply for %s\n", rdev->supply_name, rdev->desc->name); - return -EPROBE_DEFER; + ret = -EPROBE_DEFER; + goto out; } } if (r == rdev) { dev_err(dev, "Supply for %s (%s) resolved to itself\n", rdev->desc->name, rdev->supply_name); - if (!have_full_constraints()) - return -EINVAL; + if (!have_full_constraints()) { + ret = -EINVAL; + goto out; + } r = dummy_regulator_rdev; get_device(&r->dev); } @@ -1859,7 +1862,8 @@ static int regulator_resolve_supply(struct regulator_dev *rdev) if (r->dev.parent && r->dev.parent != rdev->dev.parent) { if (!device_is_bound(r->dev.parent)) { put_device(&r->dev); - return -EPROBE_DEFER; + ret = -EPROBE_DEFER; + goto out; } } @@ -1867,15 +1871,32 @@ static int regulator_resolve_supply(struct regulator_dev *rdev) ret = regulator_resolve_supply(r); if (ret < 0) { put_device(&r->dev); - return ret; + goto out; + } + + /* + * Recheck rdev->supply with rdev->mutex lock held to avoid a race + * between rdev->supply null check and setting rdev->supply in + * set_supply() from concurrent tasks. + */ + regulator_lock(rdev); + + /* Supply just resolved by a concurrent task? */ + if (rdev->supply) { + regulator_unlock(rdev); + put_device(&r->dev); + goto out; } ret = set_supply(rdev, r); if (ret < 0) { + regulator_unlock(rdev); put_device(&r->dev); - return ret; + goto out; } + regulator_unlock(rdev); + /* * In set_machine_constraints() we may have turned this regulator on * but we couldn't propagate to the supply if it hadn't been resolved @@ -1886,11 +1907,12 @@ static int regulator_resolve_supply(struct regulator_dev *rdev) if (ret < 0) { _regulator_put(rdev->supply); rdev->supply = NULL; - return ret; + goto out; } } - return 0; +out: + return ret; } /* Internal regulator request function */ diff --git a/include/linux/regulator/consumer.h b/include/linux/regulator/consumer.h index 2024944fd2f7..20e84a84fb77 100644 --- a/include/linux/regulator/consumer.h +++ b/include/linux/regulator/consumer.h @@ -331,6 +331,12 @@ regulator_get_exclusive(struct device *dev, const char *id) return ERR_PTR(-ENODEV); } +static inline struct regulator *__must_check +devm_regulator_get_exclusive(struct device *dev, const char *id) +{ + return ERR_PTR(-ENODEV); +} + static inline struct regulator *__must_check regulator_get_optional(struct device *dev, const char *id) { @@ -486,6 +492,11 @@ static inline int regulator_get_voltage(struct regulator *regulator) return -EINVAL; } +static inline int regulator_sync_voltage(struct regulator *regulator) +{ + return -EINVAL; +} + static inline int regulator_is_supported_voltage(struct regulator *regulator, int min_uV, int max_uV) { @@ -578,6 +589,25 @@ static inline int devm_regulator_unregister_notifier(struct regulator *regulator return 0; } +static inline int regulator_suspend_enable(struct regulator_dev *rdev, + suspend_state_t state) +{ + return -EINVAL; +} + +static inline int regulator_suspend_disable(struct regulator_dev *rdev, + suspend_state_t state) +{ + return -EINVAL; +} + +static inline int regulator_set_suspend_voltage(struct regulator *regulator, + int min_uV, int max_uV, + suspend_state_t state) +{ + return -EINVAL; +} + static inline void *regulator_get_drvdata(struct regulator *regulator) { return NULL;