1 files changed, 11 insertions, 7 deletions

diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index dfe7c8e1b185..ae5ec76dca77 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -63,7 +63,7 @@ static acpi_status acpi_run_osc(acpi_handle handle,
         union acpi_object in_params[4];
         struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
         union acpi_object *out_obj;
-        u32 osc_dw0, flags = osc_args->capbuf[OSC_QUERY_TYPE];
+        u32 errors, flags = osc_args->capbuf[OSC_QUERY_TYPE];
 
         /* Setting up input parameters */
         input.count = 4;
@@ -83,21 +83,25 @@ static acpi_status acpi_run_osc(acpi_handle handle,
         if (ACPI_FAILURE(status))
                 return status;
 
+        if (!output.length)
+                return AE_NULL_OBJECT;
+
         out_obj = output.pointer;
         if (out_obj->type != ACPI_TYPE_BUFFER) {
                 printk(KERN_DEBUG "Evaluate _OSC returns wrong type\n");
                 status = AE_TYPE;
                 goto out_kfree;
         }
-        osc_dw0 = *((u32 *)out_obj->buffer.pointer);
-        if (osc_dw0) {
-                if (osc_dw0 & OSC_REQUEST_ERROR)
+        /* Need to ignore the bit0 in result code */
+        errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
+        if (errors) {
+                if (errors & OSC_REQUEST_ERROR)
                         printk(KERN_DEBUG "_OSC request fails\n"); 
-                if (osc_dw0 & OSC_INVALID_UUID_ERROR)
+                if (errors & OSC_INVALID_UUID_ERROR)
                         printk(KERN_DEBUG "_OSC invalid UUID\n"); 
-                if (osc_dw0 & OSC_INVALID_REVISION_ERROR)
+                if (errors & OSC_INVALID_REVISION_ERROR)
                         printk(KERN_DEBUG "_OSC invalid revision\n"); 
-                if (osc_dw0 & OSC_CAPABILITIES_MASK_ERROR) {
+                if (errors & OSC_CAPABILITIES_MASK_ERROR) {
                         if (flags & OSC_QUERY_ENABLE)
                                 goto out_success;
                         printk(KERN_DEBUG "_OSC FW not grant req. control\n");