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>

diff --git a/drivers/acpi/pci_slot.c b/drivers/acpi/pci_slot.c
index dd376f7..d5b4ef8 100644 (file)
--- 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);