[PATCH] RTC: Remove RTC UIP synchronization on MIPS MC146818

Signed-off-by: Matt Mackall <mpm@selenic.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 31 deletions

diff --git a/include/asm-mips/mc146818-time.h b/include/asm-mips/mc146818-time.h
index 47214861093..41ac8d363c6 100644
--- a/include/asm-mips/mc146818-time.h
+++ b/include/asm-mips/mc146818-time.h
@@ -86,43 +86,14 @@ static inline int mc146818_set_rtc_mmss(unsigned long nowtime)
         return retval;
 }
 
-/*
- * Returns true if a clock update is in progress
- */
-static inline unsigned char rtc_is_updating(void)
-{
-        unsigned char uip;
-        unsigned long flags;
-
-        spin_lock_irqsave(&rtc_lock, flags);
-        uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP);
-        spin_unlock_irqrestore(&rtc_lock, flags);
-        return uip;
-}
-
 static inline unsigned long mc146818_get_cmos_time(void)
 {
         unsigned int year, mon, day, hour, min, sec;
-        int i;
         unsigned long flags;
 
-        /*
-         * The Linux interpretation of the CMOS clock register contents:
-         * When the Update-In-Progress (UIP) flag goes from 1 to 0, the
-         * RTC registers show the second which has precisely just started.
-         * Let's hope other operating systems interpret the RTC the same way.
-         */
-
-        /* read RTC exactly on falling edge of update flag */
-        for (i = 0 ; i < 1000000 ; i++) /* may take up to 1 second... */
-                if (rtc_is_updating())
-                        break;
-        for (i = 0 ; i < 1000000 ; i++) /* must try at least 2.228 ms */
-                if (!rtc_is_updating())
-                        break;
-
         spin_lock_irqsave(&rtc_lock, flags);
-        do { /* Isn't this overkill ? UIP above should guarantee consistency */
+
+        do {
                 sec = CMOS_READ(RTC_SECONDS);
                 min = CMOS_READ(RTC_MINUTES);
                 hour = CMOS_READ(RTC_HOURS);