linux-kernel - [PATCH 03/18] clocksource/drivers/exynos_mct: Move one-shot check from tick clear to ISR

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Date:   Sat, 23 Feb 2019 14:06:51 +0100
From:   Daniel Lezcano <daniel.lezcano@...aro.org>
To:     tglx@...utronix.de
Cc:     linux-kernel@...r.kernel.org,
        Stuart Menefy <stuart.menefy@...hembedded.com>,
        stable@...r.kernel.org,
        Marek Szyprowski <m.szyprowski@...sung.com>,
        Kukjin Kim <kgene@...nel.org>,
        Krzysztof Kozlowski <krzk@...nel.org>,
        linux-arm-kernel@...ts.infradead.org (moderated list:ARM/SAMSUNG EXYNOS
        ARM ARCHITECTURES),
        linux-samsung-soc@...r.kernel.org (moderated list:ARM/SAMSUNG EXYNOS
        ARM ARCHITECTURES)
Subject: [PATCH 03/18] clocksource/drivers/exynos_mct: Move one-shot check from tick clear to ISR

From: Stuart Menefy <stuart.menefy@...hembedded.com>

When a timer tick occurs and the clock is in one-shot mode, the timer
needs to be stopped to prevent it triggering subsequent interrupts.
Currently this code is in exynos4_mct_tick_clear(), but as it is
only needed when an ISR occurs move it into exynos4_mct_tick_isr(),
leaving exynos4_mct_tick_clear() just doing what its name suggests it
should.

Signed-off-by: Stuart Menefy <stuart.menefy@...hembedded.com>
Reviewed-by: Krzysztof Kozlowski <krzk@...nel.org>
Tested-by: Marek Szyprowski <m.szyprowski@...sung.com>
Cc: stable@...r.kernel.org # v4.3+
Signed-off-by: Daniel Lezcano <daniel.lezcano@...aro.org>
---
 drivers/clocksource/exynos_mct.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c
index 7a244b681876..1e325f89d408 100644
--- a/drivers/clocksource/exynos_mct.c
+++ b/drivers/clocksource/exynos_mct.c
@@ -388,6 +388,13 @@ static void exynos4_mct_tick_start(unsigned long cycles,
 	exynos4_mct_write(tmp, mevt->base + MCT_L_TCON_OFFSET);
 }
 
+static void exynos4_mct_tick_clear(struct mct_clock_event_device *mevt)
+{
+	/* Clear the MCT tick interrupt */
+	if (readl_relaxed(reg_base + mevt->base + MCT_L_INT_CSTAT_OFFSET) & 1)
+		exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET);
+}
+
 static int exynos4_tick_set_next_event(unsigned long cycles,
 				       struct clock_event_device *evt)
 {
@@ -420,8 +427,11 @@ static int set_state_periodic(struct clock_event_device *evt)
 	return 0;
 }
 
-static void exynos4_mct_tick_clear(struct mct_clock_event_device *mevt)
+static irqreturn_t exynos4_mct_tick_isr(int irq, void *dev_id)
 {
+	struct mct_clock_event_device *mevt = dev_id;
+	struct clock_event_device *evt = &mevt->evt;
+
 	/*
 	 * This is for supporting oneshot mode.
 	 * Mct would generate interrupt periodically
@@ -430,16 +440,6 @@ static void exynos4_mct_tick_clear(struct mct_clock_event_device *mevt)
 	if (!clockevent_state_periodic(&mevt->evt))
 		exynos4_mct_tick_stop(mevt);
 
-	/* Clear the MCT tick interrupt */
-	if (readl_relaxed(reg_base + mevt->base + MCT_L_INT_CSTAT_OFFSET) & 1)
-		exynos4_mct_write(0x1, mevt->base + MCT_L_INT_CSTAT_OFFSET);
-}
-
-static irqreturn_t exynos4_mct_tick_isr(int irq, void *dev_id)
-{
-	struct mct_clock_event_device *mevt = dev_id;
-	struct clock_event_device *evt = &mevt->evt;
-
 	exynos4_mct_tick_clear(mevt);
 
 	evt->event_handler(evt);
-- 
2.17.1