1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/char/watchdog/ibmasr.c b/drivers/char/watchdog/ibmasr.c
index a32c073d29bc..4f90015be7dd 100644
--- a/drivers/char/watchdog/ibmasr.c
+++ b/drivers/char/watchdog/ibmasr.c
@@ -267,7 +267,10 @@ static int asr_ioctl(struct inode *inode, struct file *file,
                         asr_toggle();
                         return 0;
 
-
+                /*
+                 * The hardware has a fixed timeout value, so WDIOC_SETTIMEOUT
+                 * is a noop and WDIOC_GETTIMEOUT always returns 256.
+                 */
                 case WDIOC_SETTIMEOUT:
                         if (get_user(heartbeat, p))
                                 return -EFAULT;