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/ddb5xxx/common/rtc_ds1386.c b/arch/mips/ddb5xxx/common/rtc_ds1386.c
index f5b11508ff2f..995896ac0e39 100644
--- a/arch/mips/ddb5xxx/common/rtc_ds1386.c
+++ b/arch/mips/ddb5xxx/common/rtc_ds1386.c
@@ -41,7 +41,9 @@ rtc_ds1386_get_time(void)
         u8 byte;
         u8 temp;
         unsigned int year, month, day, hour, minute, second;
+        unsigned long flags;
 
+        spin_lock_irqsave(&rtc_lock, flags);
         /* let us freeze external registers */
         byte = READ_RTC(0xB);
         byte &= 0x3f;
@@ -60,6 +62,7 @@ rtc_ds1386_get_time(void)
         /* enable time transfer */
         byte |= 0x80;
         WRITE_RTC(0xB, byte);
+        spin_unlock_irqrestore(&rtc_lock, flags);
 
         /* calc hour */
         if (temp & 0x40) {
@@ -81,7 +84,9 @@ rtc_ds1386_set_time(unsigned long t)
         u8 byte;
         u8 temp;
         u8 year, month, day, hour, minute, second;
+        unsigned long flags;
 
+        spin_lock_irqsave(&rtc_lock, flags);
         /* let us freeze external registers */
         byte = READ_RTC(0xB);
         byte &= 0x3f;
@@ -133,6 +138,7 @@ rtc_ds1386_set_time(unsigned long t)
         if (second != READ_RTC(0x1)) {
                 WRITE_RTC(0x1, second);
         }
+        spin_unlock_irqrestore(&rtc_lock, flags);
 
         return 0;
 }