From: Mark Brown <broonie@kernel.org>
Date: Mon, 19 Nov 2018 13:16:15 +0000 (+0000)
Subject: Merge branch 'topic/coupled' of https://git.kernel.org/pub/scm/linux/kernel/git/broon... 
X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=ffb8c1e45e7ae648a3a1689aa71be50fb459316e;p=openwrt%2Fstaging%2Fblogic.git

Merge branch 'topic/coupled' of https://git./linux/kernel/git/broonie/regulator into regulator-4.21 for trivial conflict
---

ffb8c1e45e7ae648a3a1689aa71be50fb459316e
diff --cc drivers/regulator/core.c
index 55207264c212,fd237bc0fa7c..d7ffd7b12472
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@@ -209,55 -334,46 +334,77 @@@ static void regulator_unlock_dependent(
  }
  
  /**
-  * regulator_unlock_supply - unlock a regulator and its supplies
-  * @rdev:         regulator source
+  * regulator_lock_dependent - lock regulator's suppliers and coupled regulators
+  * @rdev:			regulator source
+  * @ww_ctx:			w/w mutex acquire context
+  *
+  * This function as a wrapper on regulator_lock_recursive(), which locks
+  * all regulators related with rdev by coupling or suppling.
   */
- static void regulator_unlock_supply(struct regulator_dev *rdev)
+ static void regulator_lock_dependent(struct regulator_dev *rdev,
+ 				     struct ww_acquire_ctx *ww_ctx)
  {
- 	struct regulator *supply;
+ 	struct regulator_dev *new_contended_rdev = NULL;
+ 	struct regulator_dev *old_contended_rdev = NULL;
+ 	int err;
  
- 	while (1) {
- 		regulator_unlock(rdev);
- 		supply = rdev->supply;
+ 	mutex_lock(&regulator_list_mutex);
  
- 		if (!rdev->supply)
- 			return;
+ 	ww_acquire_init(ww_ctx, &regulator_ww_class);
  
- 		rdev = supply->rdev;
- 	}
+ 	do {
+ 		if (new_contended_rdev) {
+ 			ww_mutex_lock_slow(&new_contended_rdev->mutex, ww_ctx);
+ 			old_contended_rdev = new_contended_rdev;
+ 			old_contended_rdev->ref_cnt++;
+ 		}
+ 
+ 		err = regulator_lock_recursive(rdev,
+ 					       &new_contended_rdev,
+ 					       &old_contended_rdev,
+ 					       ww_ctx);
+ 
+ 		if (old_contended_rdev)
+ 			regulator_unlock(old_contended_rdev);
+ 
+ 	} while (err == -EDEADLK);
+ 
+ 	ww_acquire_done(ww_ctx);
+ 
+ 	mutex_unlock(&regulator_list_mutex);
  }
  
 +/**
 + * of_get_child_regulator - get a child regulator device node
 + * based on supply name
 + * @parent: Parent device node
 + * @prop_name: Combination regulator supply name and "-supply"
 + *
 + * Traverse all child nodes.
 + * Extract the child regulator device node corresponding to the supply name.
 + * returns the device node corresponding to the regulator if found, else
 + * returns NULL.
 + */
 +static struct device_node *of_get_child_regulator(struct device_node *parent,
 +						  const char *prop_name)
 +{
 +	struct device_node *regnode = NULL;
 +	struct device_node *child = NULL;
 +
 +	for_each_child_of_node(parent, child) {
 +		regnode = of_parse_phandle(child, prop_name, 0);
 +
 +		if (!regnode) {
 +			regnode = of_get_child_regulator(child, prop_name);
 +			if (regnode)
 +				return regnode;
 +		} else {
 +			return regnode;
 +		}
 +	}
 +	return NULL;
 +}
 +
  /**
   * of_get_regulator - get a regulator device node based on supply name
   * @dev: Device pointer for the consumer (of regulator) device