ACPI: scan: Simplify initialization of power and sleep buttons

It should be perfectly fine to use ACPI if the "fixed" power or sleep
buttons cannot be initialized.  Moreover, running acpi_bus_scan()
successfully on ACPI_ROOT_OBJECT generally causes many devices to
be enumerated and probed, possibly including the entire PCI bus, so
unregistering acpi_root if the registration of the "fixed" buttons
fails is rather unhelpful.

For this reason, do not fail acpi_scan_init() when
acpi_bus_scan_fixed() fails and turn the latter into a void function.

While at it, drop the outdated and misleading comment from
acpi_bus_scan_fixed().

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 7e7417f4df22b2f91b9356dd5da3fc69bbe1d21f..81ee565f47cd614234d1ba95e4ca82d41d1c27d5 100644 (file)
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -2486,42 +2486,33 @@ int acpi_bus_register_early_device(int type)
 }
 EXPORT_SYMBOL_GPL(acpi_bus_register_early_device);
 
-static int acpi_bus_scan_fixed(void)
+static void acpi_bus_scan_fixed(void)
 {
-       int result = 0;
-
-       /*
-        * Enumerate all fixed-feature devices.
-        */
        if (!(acpi_gbl_FADT.flags & ACPI_FADT_POWER_BUTTON)) {
-               struct acpi_device *device = NULL;
-
-               result = acpi_add_single_object(&device, NULL,
-                                               ACPI_BUS_TYPE_POWER_BUTTON, false);
-               if (result)
-                       return result;
-
-               device->flags.match_driver = true;
-               result = device_attach(&device->dev);
-               if (result < 0)
-                       return result;
-
-               device_init_wakeup(&device->dev, true);
+               struct acpi_device *adev = NULL;
+
+               acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_POWER_BUTTON,
+                                      false);
+               if (adev) {
+                       adev->flags.match_driver = true;
+                       if (device_attach(&adev->dev) >= 0)
+                               device_init_wakeup(&adev->dev, true);
+                       else
+                               dev_dbg(&adev->dev, "No driver\n");
+               }
        }
 
        if (!(acpi_gbl_FADT.flags & ACPI_FADT_SLEEP_BUTTON)) {
-               struct acpi_device *device = NULL;
-
-               result = acpi_add_single_object(&device, NULL,
-                                               ACPI_BUS_TYPE_SLEEP_BUTTON, false);
-               if (result)
-                       return result;
-
-               device->flags.match_driver = true;
-               result = device_attach(&device->dev);
+               struct acpi_device *adev = NULL;
+
+               acpi_add_single_object(&adev, NULL, ACPI_BUS_TYPE_SLEEP_BUTTON,
+                                      false);
+               if (adev) {
+                       adev->flags.match_driver = true;
+                       if (device_attach(&adev->dev) < 0)
+                               dev_dbg(&adev->dev, "No driver\n");
+               }
        }
-
-       return result < 0 ? result : 0;
 }
 
 static void __init acpi_get_spcr_uart_addr(void)
@@ -2601,15 +2592,8 @@ void __init acpi_scan_init(void)
                goto out;
 
        /* Fixed feature devices do not exist on HW-reduced platform */
-       if (!acpi_gbl_reduced_hardware) {
-               if (acpi_bus_scan_fixed()) {
-                       acpi_detach_data(acpi_root->handle,
-                                        acpi_scan_drop_device);
-                       acpi_device_del(acpi_root);
-                       acpi_bus_put_acpi_device(acpi_root);
-                       goto out;
-               }
-       }
+       if (!acpi_gbl_reduced_hardware)
+               acpi_bus_scan_fixed();
 
        acpi_turn_off_unused_power_resources();