diff options
Diffstat (limited to 'drivers/regulator/core.c')
| -rw-r--r-- | drivers/regulator/core.c | 93 |
1 files changed, 81 insertions, 12 deletions
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 4fcd36055b02..dc741ac156c3 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -207,6 +207,71 @@ static void regulator_unlock(struct regulator_dev *rdev) mutex_unlock(®ulator_nesting_mutex); } +/** + * regulator_lock_two - lock two regulators + * @rdev1: first regulator + * @rdev2: second regulator + * @ww_ctx: w/w mutex acquire context + * + * Locks both rdevs using the regulator_ww_class. + */ +static void regulator_lock_two(struct regulator_dev *rdev1, + struct regulator_dev *rdev2, + struct ww_acquire_ctx *ww_ctx) +{ + struct regulator_dev *held, *contended; + int ret; + + ww_acquire_init(ww_ctx, ®ulator_ww_class); + + /* Try to just grab both of them */ + ret = regulator_lock_nested(rdev1, ww_ctx); + WARN_ON(ret); + ret = regulator_lock_nested(rdev2, ww_ctx); + if (ret != -EDEADLOCK) { + WARN_ON(ret); + goto exit; + } + + held = rdev1; + contended = rdev2; + while (true) { + regulator_unlock(held); + + ww_mutex_lock_slow(&contended->mutex, ww_ctx); + contended->ref_cnt++; + contended->mutex_owner = current; + swap(held, contended); + ret = regulator_lock_nested(contended, ww_ctx); + + if (ret != -EDEADLOCK) { + WARN_ON(ret); + break; + } + } + +exit: + ww_acquire_done(ww_ctx); +} + +/** + * regulator_unlock_two - unlock two regulators + * @rdev1: first regulator + * @rdev2: second regulator + * @ww_ctx: w/w mutex acquire context + * + * The inverse of regulator_lock_two(). + */ + +static void regulator_unlock_two(struct regulator_dev *rdev1, + struct regulator_dev *rdev2, + struct ww_acquire_ctx *ww_ctx) +{ + regulator_unlock(rdev2); + regulator_unlock(rdev1); + ww_acquire_fini(ww_ctx); +} + static bool regulator_supply_is_couple(struct regulator_dev *rdev) { struct regulator_dev *c_rdev; @@ -334,6 +399,7 @@ static void regulator_lock_dependent(struct regulator_dev *rdev, ww_mutex_lock_slow(&new_contended_rdev->mutex, ww_ctx); old_contended_rdev = new_contended_rdev; old_contended_rdev->ref_cnt++; + old_contended_rdev->mutex_owner = current; } err = regulator_lock_recursive(rdev, @@ -1583,9 +1649,6 @@ static int set_machine_constraints(struct regulator_dev *rdev) rdev->constraints->always_on = true; } - if (rdev->desc->off_on_delay) - rdev->last_off = ktime_get_boottime(); - /* If the constraints say the regulator should be on at this point * and we have control then make sure it is enabled. */ @@ -1619,6 +1682,8 @@ static int set_machine_constraints(struct regulator_dev *rdev) if (rdev->constraints->always_on) rdev->use_count++; + } else if (rdev->desc->off_on_delay) { + rdev->last_off = ktime_get(); } print_constraints(rdev); @@ -1627,8 +1692,8 @@ static int set_machine_constraints(struct regulator_dev *rdev) /** * set_supply - set regulator supply regulator - * @rdev: regulator name - * @supply_rdev: supply regulator name + * @rdev: regulator (locked) + * @supply_rdev: supply regulator (locked)) * * Called by platform initialisation code to set the supply regulator for this * regulator. This ensures that a regulators supply will also be enabled by the @@ -1800,6 +1865,8 @@ static struct regulator *create_regulator(struct regulator_dev *rdev, struct regulator *regulator; int err = 0; + lockdep_assert_held_once(&rdev->mutex.base); + if (dev) { char buf[REG_STR_SIZE]; int size; @@ -1827,9 +1894,7 @@ static struct regulator *create_regulator(struct regulator_dev *rdev, regulator->rdev = rdev; regulator->supply_name = supply_name; - regulator_lock(rdev); list_add(®ulator->list, &rdev->consumer_list); - regulator_unlock(rdev); if (dev) { regulator->dev = dev; @@ -1995,6 +2060,7 @@ static int regulator_resolve_supply(struct regulator_dev *rdev) { struct regulator_dev *r; struct device *dev = rdev->dev.parent; + struct ww_acquire_ctx ww_ctx; int ret = 0; /* No supply to resolve? */ @@ -2061,23 +2127,23 @@ static int regulator_resolve_supply(struct regulator_dev *rdev) * between rdev->supply null check and setting rdev->supply in * set_supply() from concurrent tasks. */ - regulator_lock(rdev); + regulator_lock_two(rdev, r, &ww_ctx); /* Supply just resolved by a concurrent task? */ if (rdev->supply) { - regulator_unlock(rdev); + regulator_unlock_two(rdev, r, &ww_ctx); put_device(&r->dev); goto out; } ret = set_supply(rdev, r); if (ret < 0) { - regulator_unlock(rdev); + regulator_unlock_two(rdev, r, &ww_ctx); put_device(&r->dev); goto out; } - regulator_unlock(rdev); + regulator_unlock_two(rdev, r, &ww_ctx); /* * In set_machine_constraints() we may have turned this regulator on @@ -2190,7 +2256,9 @@ struct regulator *_regulator_get(struct device *dev, const char *id, return regulator; } + regulator_lock(rdev); regulator = create_regulator(rdev, dev, id); + regulator_unlock(rdev); if (regulator == NULL) { regulator = ERR_PTR(-ENOMEM); module_put(rdev->owner); @@ -2668,7 +2736,7 @@ static int _regulator_do_enable(struct regulator_dev *rdev) trace_regulator_enable(rdev_get_name(rdev)); - if (rdev->desc->off_on_delay && rdev->last_off) { + if (rdev->desc->off_on_delay) { /* if needed, keep a distance of off_on_delay from last time * this regulator was disabled. */ @@ -6049,6 +6117,7 @@ static void regulator_summary_lock(struct ww_acquire_ctx *ww_ctx) ww_mutex_lock_slow(&new_contended_rdev->mutex, ww_ctx); old_contended_rdev = new_contended_rdev; old_contended_rdev->ref_cnt++; + old_contended_rdev->mutex_owner = current; } err = regulator_summary_lock_all(ww_ctx, |