sony-laptop: Avoid oops on module unload for older laptops

Older VAIO laptops without the SN00 ACPI method will have the "handles"
variable unset. Return early from sony_nc_function_cleanup when "handles"
is null.

Signed-off-by: Lawrence Yiu <lawyiu.dev@gmail.com>
Acked-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>

diff --git a/drivers/platform/x86/sony-laptop.c b/drivers/platform/x86/sony-laptop.c
index e9caa34..1dba359 100644 (file)
--- a/drivers/platform/x86/sony-laptop.c
+++ b/drivers/platform/x86/sony-laptop.c
@@ -1446,6 +1446,9 @@ static void sony_nc_function_cleanup(struct platform_device *pd)
 {
        unsigned int i, result, bitmask, handle;
 
+       if (!handles)
+               return;
+
        /* get enabled events and disable them */
        sony_nc_int_call(sony_nc_acpi_handle, "SN01", NULL, &bitmask);
        sony_nc_int_call(sony_nc_acpi_handle, "SN03", &bitmask, &result);