ACPI: fix OSC regression that caused aer and pciehp not to load

Executing _OSC returns a buffer, which has an acpi object in it.
Don't directly returns the buffer, instead, we return the acpi object's
buffer. This fixes a regression since caller of acpi_run_osc expects
an acpi object's buffer returned.

Tested-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 65f7e33..0c1ad31 100644 (file)
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -397,6 +397,7 @@ acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context)
        union acpi_object *out_obj;
        u8 uuid[16];
        u32 errors;
+       struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
 
        if (!context)
                return AE_ERROR;
@@ -419,16 +420,16 @@ acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context)
        in_params[3].buffer.length      = context->cap.length;
        in_params[3].buffer.pointer     = context->cap.pointer;
 
-       status = acpi_evaluate_object(handle, "_OSC", &input, &context->ret);
+       status = acpi_evaluate_object(handle, "_OSC", &input, &output);
        if (ACPI_FAILURE(status))
                return status;
 
-       /* return buffer should have the same length as cap buffer */
-       if (context->ret.length != context->cap.length)
+       if (!output.length)
                return AE_NULL_OBJECT;
 
-       out_obj = context->ret.pointer;
-       if (out_obj->type != ACPI_TYPE_BUFFER) {
+       out_obj = output.pointer;
+       if (out_obj->type != ACPI_TYPE_BUFFER
+               || out_obj->buffer.length != context->cap.length) {
                acpi_print_osc_error(handle, context,
                        "_OSC evaluation returned wrong type");
                status = AE_TYPE;
@@ -457,11 +458,20 @@ acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context)
                goto out_kfree;
        }
 out_success:
-       return AE_OK;
+       context->ret.length = out_obj->buffer.length;
+       context->ret.pointer = kmalloc(context->ret.length, GFP_KERNEL);
+       if (!context->ret.pointer) {
+               status =  AE_NO_MEMORY;
+               goto out_kfree;
+       }
+       memcpy(context->ret.pointer, out_obj->buffer.pointer,
+               context->ret.length);
+       status =  AE_OK;
 
 out_kfree:
-       kfree(context->ret.pointer);
-       context->ret.pointer = NULL;
+       kfree(output.pointer);
+       if (status != AE_OK)
+               context->ret.pointer = NULL;
        return status;
 }
 EXPORT_SYMBOL(acpi_run_osc);