1 files changed, 56 insertions, 28 deletions

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 3aa18737470f..40e5f29a2670 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -2473,47 +2473,73 @@ err:
 
 }
 
-static int _opp_set_required_devs(struct opp_table *opp_table,
-				  struct device *dev,
-				  struct device **required_devs)
+static int _opp_set_required_dev(struct opp_table *opp_table,
+				 struct device *dev,
+				 struct device *required_dev,
+				 unsigned int index)
 {
-	int i;
+	struct opp_table *required_table, *pd_table;
+	struct device *gdev;
 
-	if (!opp_table->required_devs) {
+	/* Genpd core takes care of propagation to parent genpd */
+	if (opp_table->is_genpd) {
+		dev_err(dev, "%s: Operation not supported for genpds\n", __func__);
+		return -EOPNOTSUPP;
+	}
+
+	if (index >= opp_table->required_opp_count) {
 		dev_err(dev, "Required OPPs not available, can't set required devs\n");
 		return -EINVAL;
 	}
 
-	/* Another device that shares the OPP table has set the required devs ? */
-	if (opp_table->required_devs[0])
-		return 0;
+	required_table = opp_table->required_opp_tables[index];
+	if (IS_ERR(required_table)) {
+		dev_err(dev, "Missing OPP table, unable to set the required devs\n");
+		return -ENODEV;
+	}
 
-	for (i = 0; i < opp_table->required_opp_count; i++) {
-		/* Genpd core takes care of propagation to parent genpd */
-		if (required_devs[i] && opp_table->is_genpd &&
-		    opp_table->required_opp_tables[i]->is_genpd) {
-			dev_err(dev, "%s: Operation not supported for genpds\n", __func__);
-			return -EOPNOTSUPP;
+	/*
+	 * The required_opp_tables parsing is not perfect, as the OPP core does
+	 * the parsing solely based on the DT node pointers. The core sets the
+	 * required_opp_tables entry to the first OPP table in the "opp_tables"
+	 * list, that matches with the node pointer.
+	 *
+	 * If the target DT OPP table is used by multiple devices and they all
+	 * create separate instances of 'struct opp_table' from it, then it is
+	 * possible that the required_opp_tables entry may be set to the
+	 * incorrect sibling device.
+	 *
+	 * Cross check it again and fix if required.
+	 */
+	gdev = dev_to_genpd_dev(required_dev);
+	if (IS_ERR(gdev))
+		return PTR_ERR(gdev);
+
+	pd_table = _find_opp_table(gdev);
+	if (!IS_ERR(pd_table)) {
+		if (pd_table != required_table) {
+			dev_pm_opp_put_opp_table(required_table);
+			opp_table->required_opp_tables[index] = pd_table;
+		} else {
+			dev_pm_opp_put_opp_table(pd_table);
 		}
-
-		opp_table->required_devs[i] = required_devs[i];
 	}
 
+	opp_table->required_devs[index] = required_dev;
 	return 0;
 }
 
-static void _opp_put_required_devs(struct opp_table *opp_table)
+static void _opp_put_required_dev(struct opp_table *opp_table,
+				  unsigned int index)
 {
-	int i;
-
-	for (i = 0; i < opp_table->required_opp_count; i++)
-		opp_table->required_devs[i] = NULL;
+	opp_table->required_devs[index] = NULL;
 }
 
 static void _opp_clear_config(struct opp_config_data *data)
 {
-	if (data->flags & OPP_CONFIG_REQUIRED_DEVS)
-		_opp_put_required_devs(data->opp_table);
+	if (data->flags & OPP_CONFIG_REQUIRED_DEV)
+		_opp_put_required_dev(data->opp_table,
+				      data->required_dev_index);
 	else if (data->flags & OPP_CONFIG_GENPD)
 		_opp_detach_genpd(data->opp_table);
 
@@ -2630,7 +2656,7 @@ int dev_pm_opp_set_config(struct device *dev, struct dev_pm_opp_config *config)
 
 	/* Attach genpds */
 	if (config->genpd_names) {
-		if (config->required_devs) {
+		if (config->required_dev) {
 			ret = -EINVAL;
 			goto err;
 		}
@@ -2641,13 +2667,15 @@ int dev_pm_opp_set_config(struct device *dev, struct dev_pm_opp_config *config)
 			goto err;
 
 		data->flags |= OPP_CONFIG_GENPD;
-	} else if (config->required_devs) {
-		ret = _opp_set_required_devs(opp_table, dev,
-					     config->required_devs);
+	} else if (config->required_dev) {
+		ret = _opp_set_required_dev(opp_table, dev,
+					    config->required_dev,
+					    config->required_dev_index);
 		if (ret)
 			goto err;
 
-		data->flags |= OPP_CONFIG_REQUIRED_DEVS;
+		data->required_dev_index = config->required_dev_index;
+		data->flags |= OPP_CONFIG_REQUIRED_DEV;
 	}
 
 	ret = xa_alloc(&opp_configs, &id, data, XA_LIMIT(1, INT_MAX),