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/momentum/jaguar_atx/setup.c b/arch/mips/momentum/jaguar_atx/setup.c
index 768bf4406452..bab192ddc185 100644
--- a/arch/mips/momentum/jaguar_atx/setup.c
+++ b/arch/mips/momentum/jaguar_atx/setup.c
@@ -149,7 +149,9 @@ arch_initcall(per_cpu_mappings);
 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 */
         rtc_base[0x7ff8] = 0x40;
 
@@ -166,6 +168,7 @@ unsigned long m48t37y_get_time(void)
 
         /* start the update */
         rtc_base[0x7ff8] = 0x00;
+        spin_unlock_irqrestore(&rtc_lock, flags);
 
         return mktime(year, month, day, hour, min, sec);
 }
@@ -173,11 +176,13 @@ 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 */
         rtc_base[0x7ff8] = 0x80;
 
@@ -201,6 +206,7 @@ int m48t37y_set_time(unsigned long sec)
 
         /* disable writing */
         rtc_base[0x7ff8] = 0x00;
+        spin_unlock_irqrestore(&rtc_lock, flags);
 
         return 0;
 }