1 files changed, 3 insertions, 1 deletions

diff --git a/arch/x86/boot/edd.c b/arch/x86/boot/edd.c
index d93cbc6464d0..bf4ae6ff518e 100644
--- a/arch/x86/boot/edd.c
+++ b/arch/x86/boot/edd.c
@@ -32,7 +32,9 @@ static int read_mbr(u8 devno, void *buf)
                      : "+a" (ax), "+c" (cx), "+d" (dx), "+b" (bx)
                      : : "esi", "edi", "memory");
 
-        return -(u8)ax;         /* 0 or -1 */
+        /* Some BIOSes do not set carry flag on error but still return
+         * error in AH. The condition below is expected to catch both */
+        return -!!ax;           /* 0 or -1 */
 }
 
 static u32 read_mbr_sig(u8 devno, struct edd_info *ei, u32 *mbrsig)