From: Matthew Garrett <mjg@redhat.com>
Date: Wed, 10 Mar 2010 19:27:46 -0500
Subject: [acpi] power_meter: avoid oops on driver load
Message-id: <1268249266-15627-1-git-send-email-mjg@redhat.com>
Patchwork-id: 23541
O-Subject: [PATCH] RHEL 5.5: Avoid oops on ACPI power meter driver load
Bugzilla: 566575
RH-Acked-by: Stanislaw Gruszka <sgruszka@redhat.com>
RH-Acked-by: Jarod Wilson <jarod@redhat.com>

bz 566575

The RHEL kernel is sufficiently old that it doesn't call device_register()
on ACPI devices, resulting in the power meter driver oopsing on probe.
Handle this at the driver level rather than performing more invasive
changes in the core.

diff --git a/drivers/acpi/power_meter.c b/drivers/acpi/power_meter.c
index 0c9e39b..001249f 100644
--- a/drivers/acpi/power_meter.c
+++ b/drivers/acpi/power_meter.c
@@ -60,6 +60,7 @@ ACPI_MODULE_NAME(ACPI_POWER_METER_NAME);
 
 static int cap_in_hardware;
 static int force_cap_on;
+static int meter_count;
 
 static int can_cap_in_hardware(void)
 {
@@ -888,6 +889,12 @@ static int acpi_power_meter_add(struct acpi_device *device)
 	if (!resource)
 		return -ENOMEM;
 
+	snprintf(device->dev.bus_id, sizeof (device->dev.bus_id),
+		 "power_meter%d", meter_count);
+	res = device_register(&device->dev);
+	if (res)
+		goto exit_free;
+
 	resource->sensors_valid = 0;
 	resource->acpi_dev = device;
 	mutex_init(&resource->lock);
@@ -898,7 +905,7 @@ static int acpi_power_meter_add(struct acpi_device *device)
 	free_capabilities(resource);
 	res = read_capabilities(resource);
 	if (res)
-		goto exit_free;
+		goto exit_unregister;
 
 	resource->trip[0] = resource->trip[1] = -1;
 
@@ -912,11 +919,14 @@ static int acpi_power_meter_add(struct acpi_device *device)
 		goto exit_remove;
 	}
 
+	meter_count++;
 	res = 0;
 	goto exit;
 
 exit_remove:
 	remove_attrs(resource);
+exit_unregister:
+	device_unregister(&device->dev);
 exit_free:
 	kfree(resource);
 exit:
@@ -940,6 +950,7 @@ static int acpi_power_meter_remove(struct acpi_device *device, int type)
 	remove_attrs(resource);
 
 	kfree(resource);
+	device_unregister(&device->dev);
 	return 0;
 }