Use rtc_lock to protect RTC operations

    
Many RTC routines were not protected against each other, so there are
potential races, for example, ntp-update against /dev/rtc.  This patch
fixes them using rtc_lock.
    
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/arch/mips/sgi-ip22/ip22-time.c b/arch/mips/sgi-ip22/ip22-time.c
index df9b5694328a..b7300cc5c5ad 100644
--- a/arch/mips/sgi-ip22/ip22-time.c
+++ b/arch/mips/sgi-ip22/ip22-time.c
@@ -35,7 +35,9 @@ static unsigned long indy_rtc_get_time(void)
 {
         unsigned int yrs, mon, day, hrs, min, sec;
         unsigned int save_control;
+        unsigned long flags;
 
+        spin_lock_irqsave(&rtc_lock, flags);
         save_control = hpc3c0->rtcregs[RTC_CMD] & 0xff;
         hpc3c0->rtcregs[RTC_CMD] = save_control | RTC_TE;
 
@@ -47,6 +49,7 @@ static unsigned long indy_rtc_get_time(void)
         yrs = BCD2BIN(hpc3c0->rtcregs[RTC_YEAR] & 0xff);
 
         hpc3c0->rtcregs[RTC_CMD] = save_control;
+        spin_unlock_irqrestore(&rtc_lock, flags);
 
         if (yrs < 45)
                 yrs += 30;
@@ -60,6 +63,7 @@ static int indy_rtc_set_time(unsigned long tim)
 {
         struct rtc_time tm;
         unsigned int save_control;
+        unsigned long flags;
 
         to_tm(tim, &tm);
 
@@ -68,6 +72,7 @@ static int indy_rtc_set_time(unsigned long tim)
         if (tm.tm_year >= 100)
                 tm.tm_year -= 100;
 
+        spin_lock_irqsave(&rtc_lock, flags);
         save_control = hpc3c0->rtcregs[RTC_CMD] & 0xff;
         hpc3c0->rtcregs[RTC_CMD] = save_control | RTC_TE;
 
@@ -80,6 +85,7 @@ static int indy_rtc_set_time(unsigned long tim)
         hpc3c0->rtcregs[RTC_HUNDREDTH_SECOND] = 0;
 
         hpc3c0->rtcregs[RTC_CMD] = save_control;
+        spin_unlock_irqrestore(&rtc_lock, flags);
 
         return 0;
 }