From c9ad8e062e4c733b36fc10ebc201bedde1a4da80 Mon Sep 17 00:00:00 2001 From: Len Brown Date: Tue, 28 Sep 2010 16:50:50 -0400 Subject: [PATCH] ACPI: acpi_pad: simplify code to avoid false gcc build warning MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 --- drivers/acpi/acpi_pad.c | 34 ++++++++++++++++++---------------- 1 file changed, 18 insertions(+), 16 deletions(-) diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c index b76848c80be..6b115f6c431 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; } -- 2.20.1