linux-kernel - [PATCH] reorder slow clock source read for clock source watchdog

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Date:   Tue, 27 Nov 2018 13:15:16 +0200
From:   Luming Yu <luming.yu@...el.com>
To:     linux-kernel@...r.kernel.org
Subject: [PATCH] reorder slow clock source read for clock source watchdog

the clock source watchdog (HPET) in skx is much slower
than the clock source TSC. The long latency in the first
call may trigger a false postive TSC unstable noise.
Let the fast one follows the slow one should fix it.

Signed-off-by: Luming Yu <luming.yu@...el.com>
Signed-off-by: Yongkai Wu <yongkaiwu@...cent.com>
---
 kernel/time/clocksource.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index ffe081623aec..8ea929e50ca6 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -225,8 +225,8 @@ static void clocksource_watchdog(struct timer_list *unused)
 		}
 
 		local_irq_disable();
-		csnow = cs->read(cs);
 		wdnow = watchdog->read(watchdog);
+		csnow = cs->read(cs);
 		local_irq_enable();
 
 		/* Clocksource initialized ? */
-- 
2.14.4