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authorLen Brown <len.brown@intel.com>2010-09-28 22:50:50 +0200
committerLen Brown <len.brown@intel.com>2010-09-29 20:08:10 +0200
commitc9ad8e062e4c733b36fc10ebc201bedde1a4da80 (patch)
tree3133de2d6ac31ddb0fc212d56cb48ed2141289dc /drivers/acpi/acpi_pad.c
parentACPI: Kconfig: fix typo. (diff)
downloadlinux-c9ad8e062e4c733b36fc10ebc201bedde1a4da80.tar.xz
linux-c9ad8e062e4c733b36fc10ebc201bedde1a4da80.zip
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>
Diffstat (limited to 'drivers/acpi/acpi_pad.c')
-rw-r--r--drivers/acpi/acpi_pad.c34
1 files changed, 18 insertions, 16 deletions
diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c
index b76848c80be3..6b115f6c4313 100644
--- 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;
}