[patch 04/14] stp synchronization retry timer

Martin Schwidefsky
2009-04-14T13:53:31Z

[-- Attachment #1: 004-stp-retry.diff --]
[-- Type: text/plain, Size: 1788 bytes --]

From: Martin Schwidefsky <schwidefsky@de.ibm.com>

Add a timer that retries the clock synchronization via the server time
protocol if there is a usable clock but the synchronization failed.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

arch/s390/kernel/time.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)

Index: quilt-2.6/arch/s390/kernel/time.c
===================================================================
--- quilt-2.6.orig/arch/s390/kernel/time.c
+++ quilt-2.6/arch/s390/kernel/time.c
@@ -1423,6 +1423,7 @@ static void *stp_page;
static void stp_work_fn(struct work_struct *work);
static DEFINE_MUTEX(stp_work_mutex);
static DECLARE_WORK(stp_work, stp_work_fn);
+static struct timer_list stp_timer;

static int __init early_parse_stp(char *p)
{
@@ -1454,10 +1455,16 @@ static void __init stp_reset(void)
}
}

+static void stp_timeout(unsigned long dummy)
+{
+ queue_work(time_sync_wq, &stp_work);
+}
+
static int __init stp_init(void)
{
if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
return 0;
+ setup_timer(&stp_timer, stp_timeout, 0UL);
time_init_wq();
if (!stp_online)
return 0;
@@ -1565,6 +1572,7 @@ static void stp_work_fn(struct work_stru

if (!stp_online) {
chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000);
+ del_timer_sync(&stp_timer);
goto out_unlock;
}

@@ -1586,6 +1594,13 @@ static void stp_work_fn(struct work_stru
stop_machine(stp_sync_clock, &stp_sync, &cpu_online_map);
put_online_cpus();

+ if (!check_sync_clock())
+ /*
+ * There is a usable clock but the synchonization failed.
+ * Retry after a second.
+ */
+ mod_timer(&stp_timer, jiffies + HZ);
+
out_unlock:
mutex_unlock(&stp_work_mutex);