From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Date: Mon, 13 Jun 2022 20:06:18 +0200
Subject: ACPI: glue: Introduce acpi_dev_has_children()
Patch-mainline: v6.0-rc1
Git-commit: f5122be80daad8e53e6876add5ccbf9db7ca809c
References: jsc#PED-1408

Define acpi_dev_has_children() as a wrapper around
acpi_dev_for_each_child() and use it to check if the given ACPI
device has any children instead of checking the children list
head in struct acpi_device.

This will help to eliminate the children list head from struct
acpi_device as it is redundant and it is used in questionable ways
in some places (in particular, locking is needed for walking the
list pointed to it safely, but it is often missing).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Lee, Chun-Yi <jlee@suse.com>
---
 drivers/acpi/glue.c |   12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

--- a/drivers/acpi/glue.c
+++ b/drivers/acpi/glue.c
@@ -77,12 +77,22 @@ static struct acpi_bus_type *acpi_get_bu
 #define FIND_CHILD_MIN_SCORE	1
 #define FIND_CHILD_MAX_SCORE	2
 
+static int match_any(struct acpi_device *adev, void *not_used)
+{
+	return 1;
+}
+
+static bool acpi_dev_has_children(struct acpi_device *adev)
+{
+	return acpi_dev_for_each_child(adev, match_any, NULL) > 0;
+}
+
 static int find_child_checks(struct acpi_device *adev, bool check_children)
 {
 	unsigned long long sta;
 	acpi_status status;
 
-	if (check_children && list_empty(&adev->children))
+	if (check_children && !acpi_dev_has_children(adev))
 		return -ENODEV;
 
 	status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta);