[PATCH] x86_64: Fix get_cmos_time()

Due to a broken condition, the body of the loop that is intended to wait for
the Update-In-Progress bit to get set and then cleared again was never
entered; in fact, the entire loop was optimized out by the compiler. Here is
a change to fix the condition (and to also move the initialization of locals
out of the spin lock protected region).

Signed-Off-By: Jan Beulich <[e-mail]>

Signed-off-by: Andi Kleen <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/x86_64/kernel/time.c

···
 
 static unsigned long get_cmos_time(void)
 {
-	unsigned int timeout, year, mon, day, hour, min, sec;
-	unsigned char last, this;
+	unsigned int timeout = 1000000, year, mon, day, hour, min, sec;
+	unsigned char uip = 0, this = 0;
 	unsigned long flags;
 
 /*
···
 
 	spin_lock_irqsave(&rtc_lock, flags);
 
-	timeout = 1000000;
-	last = this = 0;
-
-	while (timeout && last && !this) {
-		last = this;
+	while (timeout && (!uip || this)) {
+		uip |= this;
 		this = CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP;
 		timeout--;
 	}