PCI: fix bogus "'device' may be used uninitialized" warning in pci_slot

I get warnings about 'device' possibly being used uninitialised.  While
I can deduce this is not true, it seems that GCC can't.  This patch
changes `check_slot' to return device on success and -1 on error, which
shuts GCC up.

Acked-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 7 insertions, 11 deletions

diff --git a/drivers/acpi/pci_slot.c b/drivers/acpi/pci_slot.c
index dd376f7ad090..d5b4ef898879 100644
--- a/drivers/acpi/pci_slot.c
+++ b/drivers/acpi/pci_slot.c
@@ -76,9 +76,9 @@ static struct acpi_pci_driver acpi_pci_slot_driver = {
 };
 
 static int
-check_slot(acpi_handle handle, int *device, unsigned long *sun)
+check_slot(acpi_handle handle, unsigned long *sun)
 {
-        int retval = 0;
+        int device = -1;
         unsigned long adr, sta;
         acpi_status status;
         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
@@ -89,32 +89,27 @@ check_slot(acpi_handle handle, int *device, unsigned long *sun)
         if (check_sta_before_sun) {
                 /* If SxFy doesn't have _STA, we just assume it's there */
                 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
-                if (ACPI_SUCCESS(status) && !(sta & ACPI_STA_DEVICE_PRESENT)) {
-                        retval = -1;
+                if (ACPI_SUCCESS(status) && !(sta & ACPI_STA_DEVICE_PRESENT))
                         goto out;
-                }
         }
 
         status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
         if (ACPI_FAILURE(status)) {
                 dbg("_ADR returned %d on %s\n", status, (char *)buffer.pointer);
-                retval = -1;
                 goto out;
         }
 
-        *device = (adr >> 16) & 0xffff;
-
         /* No _SUN == not a slot == bail */
         status = acpi_evaluate_integer(handle, "_SUN", NULL, sun);
         if (ACPI_FAILURE(status)) {
                 dbg("_SUN returned %d on %s\n", status, (char *)buffer.pointer);
-                retval = -1;
                 goto out;
         }
 
+        device = (adr >> 16) & 0xffff;
 out:
         kfree(buffer.pointer);
-        return retval;
+        return device;
 }
 
 struct callback_args {
@@ -144,7 +139,8 @@ register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
         struct callback_args *parent_context = context;
         struct pci_bus *pci_bus = parent_context->pci_bus;
 
-        if (check_slot(handle, &device, &sun))
+        device = check_slot(handle, &sun);
+        if (device < 0)
                 return AE_OK;
 
         slot = kmalloc(sizeof(*slot), GFP_KERNEL);