Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   "Rafael J. Wysocki" <rjw@rjwysocki.net>
To:     Linux ACPI <linux-acpi@vger.kernel.org>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Linux PM <linux-pm@vger.kernel.org>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Mika Westerberg <mika.westerberg@linux.intel.com>,
        Hans de Goede <hdegoede@redhat.com>,
        Sakari Ailus <sakari.ailus@linux.intel.com>
Subject: [PATCH v2 06/16] ACPI: container: Use acpi_dev_for_each_child()
Date:   Mon, 13 Jun 2022 20:15:26 +0200
Message-ID: <10114811.nUPlyArG6x@kreacher>
In-Reply-To: <2653857.mvXUDI8C0e@kreacher>
References: <1843211.tdWV9SEqCh@kreacher> <2653857.mvXUDI8C0e@kreacher>
MIME-Version: 1.0
Content-Transfer-Encoding: 7Bit
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Instead of walking the list of children of an ACPI device directly,
use acpi_dev_for_each_child() to carry out an action for all of
the given ACPI device's children.

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>
---

v1 -> v2:
   * Do not break the acpi_dev_for_each_child() call line (Andy).
   * Add R-by from Andy.

---
 drivers/acpi/container.c |   17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

Index: linux-pm/drivers/acpi/container.c
===================================================================
--- linux-pm.orig/drivers/acpi/container.c
+++ linux-pm/drivers/acpi/container.c
@@ -23,17 +23,18 @@ static const struct acpi_device_id conta
 
 #ifdef CONFIG_ACPI_CONTAINER
 
-static int acpi_container_offline(struct container_dev *cdev)
+static int check_offline(struct acpi_device *adev, void *not_used)
 {
-	struct acpi_device *adev = ACPI_COMPANION(&cdev->dev);
-	struct acpi_device *child;
+	if (acpi_scan_is_offline(adev, false))
+		return 0;
 
-	/* Check all of the dependent devices' physical companions. */
-	list_for_each_entry(child, &adev->children, node)
-		if (!acpi_scan_is_offline(child, false))
-			return -EBUSY;
+	return -EBUSY;
+}
 
-	return 0;
+static int acpi_container_offline(struct container_dev *cdev)
+{
+	/* Check all of the dependent devices' physical companions. */
+	return acpi_dev_for_each_child(ACPI_COMPANION(&cdev->dev), check_offline, NULL);
 }
 
 static void acpi_container_release(struct device *dev)