linux-kernel - [PATCH v1 2/5] ACPI: scan: Rearrange checks in acpi_bus_check

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Date:   Wed, 07 Apr 2021 16:30:56 +0200
From:   "Rafael J. Wysocki" <rjw@...ysocki.net>
To:     Linux ACPI <linux-acpi@...r.kernel.org>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        Hans de Goede <hdegoede@...hat.com>
Subject: [PATCH v1 2/5] ACPI: scan: Rearrange checks in acpi_bus_check_add()

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

Rearrange the checks in acpi_bus_check_add() to avoid checking
the "type" twice and take "check_dep" into account only for
ACPI_TYPE_DEVICE objects.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---
 drivers/acpi/scan.c |   30 +++++++++++-------------------
 1 file changed, 11 insertions(+), 19 deletions(-)

Index: linux-pm/drivers/acpi/scan.c
===================================================================
--- linux-pm.orig/drivers/acpi/scan.c
+++ linux-pm/drivers/acpi/scan.c
@@ -1831,7 +1831,7 @@ static void acpi_scan_init_hotplug(struc
 	}
 }
 
-static u32 acpi_scan_check_dep(acpi_handle handle)
+static u32 acpi_scan_check_dep(acpi_handle handle, bool check_dep)
 {
 	struct acpi_handle_list dep_devices;
 	acpi_status status;
@@ -1844,7 +1844,8 @@ static u32 acpi_scan_check_dep(acpi_hand
 	 * 2. ACPI nodes describing USB ports.
 	 * Still, checking for _HID catches more then just these cases ...
 	 */
-	if (!acpi_has_method(handle, "_DEP") || !acpi_has_method(handle, "_HID"))
+	if (!check_dep || !acpi_has_method(handle, "_DEP") ||
+	    !acpi_has_method(handle, "_HID"))
 		return 0;
 
 	status = acpi_evaluate_reference(handle, "_DEP", NULL, &dep_devices);
@@ -1925,6 +1926,12 @@ static acpi_status acpi_bus_check_add(ac
 		if (acpi_device_should_be_hidden(handle))
 			return AE_OK;
 
+		/* Bail out if there are dependencies. */
+		if (acpi_scan_check_dep(handle, check_dep) > 0) {
+			acpi_bus_scan_second_pass = true;
+			return AE_CTRL_DEPTH;
+		}
+
 		fallthrough;
 	case ACPI_TYPE_ANY:	/* for ACPI_ROOT_OBJECT */
 		type = ACPI_BUS_TYPE_DEVICE;
@@ -1942,27 +1949,12 @@ static acpi_status acpi_bus_check_add(ac
 		break;
 
 	case ACPI_TYPE_POWER:
-		type = ACPI_BUS_TYPE_POWER;
-		break;
-
-	default:
-		return AE_OK;
-	}
-
-	if (type == ACPI_BUS_TYPE_POWER) {
 		acpi_add_power_resource(handle);
+		fallthrough;
+	default:
 		return AE_OK;
 	}
 
-	if (type == ACPI_BUS_TYPE_DEVICE && check_dep) {
-		u32 count = acpi_scan_check_dep(handle);
-		/* Bail out if the number of recorded dependencies is not 0. */
-		if (count > 0) {
-			acpi_bus_scan_second_pass = true;
-			return AE_CTRL_DEPTH;
-		}
-	}
-
 	acpi_add_single_object(&device, handle, type, sta);
 	if (!device)
 		return AE_CTRL_DEPTH;