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/pmc-sierra/yosemite/setup.c b/arch/mips/pmc-sierra/yosemite/setup.c
index bdc2ab55bed6..059755b5ed57 100644
--- a/arch/mips/pmc-sierra/yosemite/setup.c
+++ b/arch/mips/pmc-sierra/yosemite/setup.c
@@ -73,7 +73,9 @@ void __init bus_error_init(void)
 unsigned long m48t37y_get_time(void)
 {
         unsigned int year, month, day, hour, min, sec;
+        unsigned long flags;
 
+        spin_lock_irqsave(&rtc_lock, flags);
         /* Stop the update to the time */
         m48t37_base->control = 0x40;
 
@@ -88,6 +90,7 @@ unsigned long m48t37y_get_time(void)
 
         /* Start the update to the time again */
         m48t37_base->control = 0x00;
+        spin_unlock_irqrestore(&rtc_lock, flags);
 
         return mktime(year, month, day, hour, min, sec);
 }
@@ -95,11 +98,13 @@ unsigned long m48t37y_get_time(void)
 int m48t37y_set_time(unsigned long sec)
 {
         struct rtc_time tm;
+        unsigned long flags;
 
         /* convert to a more useful format -- note months count from 0 */
         to_tm(sec, &tm);
         tm.tm_mon += 1;
 
+        spin_lock_irqsave(&rtc_lock, flags);
         /* enable writing */
         m48t37_base->control = 0x80;
 
@@ -123,6 +128,7 @@ int m48t37y_set_time(unsigned long sec)
 
         /* disable writing */
         m48t37_base->control = 0x00;
+        spin_unlock_irqrestore(&rtc_lock, flags);
 
         return 0;
 }