[MIPS] Protect more of timer_interrupt() by xtime_lock.
From Dave Johnson <djohnson+linuxmips@sw.starentnetworks.com>:
* do_timer() expects the arch-specific handler to take the lock as it
modifies jiffies[_64] and xtime.
* writing timerhi/lo in timer_interrupt() will mess up
fixed_rate_gettimeoffset() which reads timerhi/lo.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/kernel/time.c b/arch/mips/kernel/time.c
index 42c94c7..51273b7 100644
--- a/arch/mips/kernel/time.c
+++ b/arch/mips/kernel/time.c
@@ -424,6 +424,8 @@
unsigned long j;
unsigned int count;
+ write_seqlock(&xtime_lock);
+
count = mips_hpt_read();
mips_timer_ack();
@@ -441,7 +443,6 @@
* CMOS clock accordingly every ~11 minutes. rtc_set_time() has to be
* called as close as possible to 500 ms before the new second starts.
*/
- write_seqlock(&xtime_lock);
if (ntp_synced() &&
xtime.tv_sec > last_rtc_update + 660 &&
(xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
@@ -453,7 +454,6 @@
last_rtc_update = xtime.tv_sec - 600;
}
}
- write_sequnlock(&xtime_lock);
/*
* If jiffies has overflown in this timer_interrupt, we must
@@ -496,6 +496,8 @@
}
}
+ write_sequnlock(&xtime_lock);
+
/*
* In UP mode, we call local_timer_interrupt() to do profiling
* and process accouting.