ACPI: acpi_pad: simplify code to avoid false gcc build warning

acpi_pad.c:432: warning: ‘num_cpus’ may be used uninitialized in this function

gcc 4.4.4 was unable to notice that num_cpus is always set.
Re-arrange the code to un-confuse gcc, and also make
it easier for humans to read....

Signed-off-by: Len Brown <len.browns@intel.com>

diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c
index b76848c80be34729c56bd20d04f75f9f534cbb36..6b115f6c43133c211acd79c68a83785506a4357a 100644 (file)
--- a/drivers/acpi/acpi_pad.c
+++ b/drivers/acpi/acpi_pad.c
@@ -382,31 +382,32 @@ static void acpi_pad_remove_sysfs(struct acpi_device *device)
        device_remove_file(&device->dev, &dev_attr_rrtime);
 }
 
-/* Query firmware how many CPUs should be idle */
-static int acpi_pad_pur(acpi_handle handle, int *num_cpus)
+/*
+ * Query firmware how many CPUs should be idle
+ * return -1 on failure
+ */
+static int acpi_pad_pur(acpi_handle handle)
 {
        struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
        union acpi_object *package;
-       int rev, num, ret = -EINVAL;
+       int num = -1;
 
        if (ACPI_FAILURE(acpi_evaluate_object(handle, "_PUR", NULL, &buffer)))
-               return -EINVAL;
+               return num;
 
        if (!buffer.length || !buffer.pointer)
-               return -EINVAL;
+               return num;
 
        package = buffer.pointer;
-       if (package->type != ACPI_TYPE_PACKAGE || package->package.count != 2)
-               goto out;
-       rev = package->package.elements[0].integer.value;
-       num = package->package.elements[1].integer.value;
-       if (rev != 1 || num < 0)
-               goto out;
-       *num_cpus = num;
-       ret = 0;
-out:
+
+       if (package->type == ACPI_TYPE_PACKAGE &&
+               package->package.count == 2 &&
+               package->package.elements[0].integer.value == 1) /* rev 1 */
+
+               num = package->package.elements[1].integer.value;
+
        kfree(buffer.pointer);
-       return ret;
+       return num;
 }
 
 /* Notify firmware how many CPUs are idle */
@@ -433,7 +434,8 @@ static void acpi_pad_handle_notify(acpi_handle handle)
        uint32_t idle_cpus;
 
        mutex_lock(&isolated_cpus_lock);
-       if (acpi_pad_pur(handle, &num_cpus)) {
+       num_cpus = acpi_pad_pur(handle);
+       if (num_cpus < 0) {
                mutex_unlock(&isolated_cpus_lock);
                return;
        }