1 files changed, 41 insertions, 7 deletions

diff --git a/drivers/gpio/gpio-sim.c b/drivers/gpio/gpio-sim.c
index f387dad81f29..686ae3d11ba3 100644
--- a/drivers/gpio/gpio-sim.c
+++ b/drivers/gpio/gpio-sim.c
@@ -1027,6 +1027,30 @@ static void gpio_sim_device_deactivate(struct gpio_sim_device *dev)
 	dev->pdev = NULL;
 }
 
+static void
+gpio_sim_device_lockup_configfs(struct gpio_sim_device *dev, bool lock)
+{
+	struct configfs_subsystem *subsys = dev->group.cg_subsys;
+	struct gpio_sim_bank *bank;
+	struct gpio_sim_line *line;
+
+	/*
+	 * The device only needs to depend on leaf line entries. This is
+	 * sufficient to lock up all the configfs entries that the
+	 * instantiated, alive device depends on.
+	 */
+	list_for_each_entry(bank, &dev->bank_list, siblings) {
+		list_for_each_entry(line, &bank->line_list, siblings) {
+			if (lock)
+				WARN_ON(configfs_depend_item_unlocked(
+						subsys, &line->group.cg_item));
+			else
+				configfs_undepend_item_unlocked(
+						&line->group.cg_item);
+		}
+	}
+}
+
 static ssize_t
 gpio_sim_device_config_live_store(struct config_item *item,
 				  const char *page, size_t count)
@@ -1039,14 +1063,24 @@ gpio_sim_device_config_live_store(struct config_item *item,
 	if (ret)
 		return ret;
 
-	guard(mutex)(&dev->lock);
+	if (live)
+		gpio_sim_device_lockup_configfs(dev, true);
 
-	if (live == gpio_sim_device_is_live(dev))
-		ret = -EPERM;
-	else if (live)
-		ret = gpio_sim_device_activate(dev);
-	else
-		gpio_sim_device_deactivate(dev);
+	scoped_guard(mutex, &dev->lock) {
+		if (live == gpio_sim_device_is_live(dev))
+			ret = -EPERM;
+		else if (live)
+			ret = gpio_sim_device_activate(dev);
+		else
+			gpio_sim_device_deactivate(dev);
+	}
+
+	/*
+	 * Undepend is required only if device disablement (live == 0)
+	 * succeeds or if device enablement (live == 1) fails.
+	 */
+	if (live == !!ret)
+		gpio_sim_device_lockup_configfs(dev, false);
 
 	return ret ?: count;
 }