1 files changed, 4 insertions, 6 deletions

diff --git a/drivers/s390/cio/blacklist.c b/drivers/s390/cio/blacklist.c
index 13cb60162e42..76058a5166ed 100644
--- a/drivers/s390/cio/blacklist.c
+++ b/drivers/s390/cio/blacklist.c
@@ -79,17 +79,15 @@ static int pure_hex(char **cp, unsigned int *val, int min_digit,
                     int max_digit, int max_val)
 {
         int diff;
-        unsigned int value;
 
         diff = 0;
         *val = 0;
 
-        while (isxdigit(**cp) && (diff <= max_digit)) {
+        while (diff <= max_digit) {
+                int value = hex_to_bin(**cp);
 
-                if (isdigit(**cp))
-                        value = **cp - '0';
-                else
-                        value = tolower(**cp) - 'a' + 10;
+                if (value < 0)
+                        break;
                 *val = *val * 16 + value;
                 (*cp)++;
                 diff++;