1 files changed, 15 insertions, 31 deletions

diff --git a/drivers/acpi/sleep/proc.c b/drivers/acpi/sleep/proc.c
index 1538355c266b..f8df5217d477 100644
--- a/drivers/acpi/sleep/proc.c
+++ b/drivers/acpi/sleep/proc.c
@@ -178,6 +178,9 @@ static int get_date_field(char **p, u32 * value)
          * Try to find delimeter, only to insert null.  The end of the
          * string won't have one, but is still valid.
          */
+        if (*p == NULL)
+                return result;
+
         next = strpbrk(*p, "- :");
         if (next)
                 *next++ = '\0';
@@ -190,6 +193,8 @@ static int get_date_field(char **p, u32 * value)
 
         if (next)
                 *p = next;
+        else
+                *p = NULL;
 
         return result;
 }
@@ -251,27 +256,6 @@ acpi_system_write_alarm(struct file *file,
         if ((result = get_date_field(&p, &sec)))
                 goto end;
 
-        if (sec > 59) {
-                min += 1;
-                sec -= 60;
-        }
-        if (min > 59) {
-                hr += 1;
-                min -= 60;
-        }
-        if (hr > 23) {
-                day += 1;
-                hr -= 24;
-        }
-        if (day > 31) {
-                mo += 1;
-                day -= 31;
-        }
-        if (mo > 12) {
-                yr += 1;
-                mo -= 12;
-        }
-
         spin_lock_irq(&rtc_lock);
 
         rtc_control = CMOS_READ(RTC_CONTROL);
@@ -288,24 +272,24 @@ acpi_system_write_alarm(struct file *file,
         spin_unlock_irq(&rtc_lock);
 
         if (sec > 59) {
-                min++;
-                sec -= 60;
+                min += sec/60;
+                sec = sec%60;
         }
         if (min > 59) {
-                hr++;
-                min -= 60;
+                hr += min/60;
+                min = min%60;
         }
         if (hr > 23) {
-                day++;
-                hr -= 24;
+                day += hr/24;
+                hr = hr%24;
         }
         if (day > 31) {
-                mo++;
-                day -= 31;
+                mo += day/32;
+                day = day%32;
         }
         if (mo > 12) {
-                yr++;
-                mo -= 12;
+                yr += mo/13;
+                mo = mo%13;
         }
 
         spin_lock_irq(&rtc_lock);