asus-wmi: handle "unknown status" bit

Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index d0f0931ea5eb..39ce3c1a7712 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -92,6 +92,7 @@ MODULE_LICENSE("GPL");
 
 /* DSTS masks */
 #define ASUS_WMI_DSTS_STATUS_BIT        0x00000001
+#define ASUS_WMI_DSTS_UNKNOWN_BIT       0x00000002
 #define ASUS_WMI_DSTS_PRESENCE_BIT      0x00010000
 #define ASUS_WMI_DSTS_BRIGHTNESS_MASK   0x000000FF
 #define ASUS_WMI_DSTS_MAX_BRIGTH_MASK   0x0000FF00
@@ -270,6 +271,11 @@ static int asus_wmi_get_devstate_bits(u32 dev_id, u32 mask)
         if (!(retval & ASUS_WMI_DSTS_PRESENCE_BIT))
                 return -ENODEV;
 
+        if (mask == ASUS_WMI_DSTS_STATUS_BIT) {
+                if (retval & ASUS_WMI_DSTS_UNKNOWN_BIT)
+                        return -ENODEV;
+        }
+
         return retval & mask;
 }