[patch added to the 3.12 stable tree] clocksource: Exynos_mct: Register clock event after request_irq()

Jiri Slaby jslaby at suse.cz
Fri Jun 6 05:49:22 PDT 2014

From: Krzysztof Kozlowski <k.kozlowski at samsung.com>

This patch has been added to the 3.12 stable tree. If you have any
objections, please let us know.


commit 8db6e5104b77de5d0b7002b95069da0992a34be9 upstream.

After hotplugging CPU1 the first call of interrupt handler for CPU1
oneshot timer was called on CPU0 because it fired before setting IRQ
affinity. Affected are SoCs where Multi Core Timer interrupts are
shared (SPI), e.g. Exynos 4210.

During setup of the MCT timers the clock event device should be
registered after setting the affinity for interrupt. This will prevent
starting the timer too early.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski at samsung.com>
Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
Cc: Kyungmin Park <kyungmin.park at samsung.com>
Cc: Marek Szyprowski <m.szyprowski at samsung.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie at samsung.com>
Cc: Tomasz Figa <t.figa at samsung.com>,
Cc: Daniel Lezcano <daniel.lezcano at linaro.org>,
Cc: Kukjin Kim <kgene.kim at samsung.com>
Cc: linux-arm-kernel at lists.infradead.org,
Link: http://lkml.kernel.org/r/20140416143316.299247848@linutronix.de
Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
Signed-off-by: Jiri Slaby <jslaby at suse.cz>
 drivers/clocksource/exynos_mct.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c
index b17b3e0981f0..70f3a597ec57 100644
--- a/drivers/clocksource/exynos_mct.c
+++ b/drivers/clocksource/exynos_mct.c
@@ -414,8 +414,6 @@ static int exynos4_local_timer_setup(struct clock_event_device *evt)
 	evt->set_mode = exynos4_tick_set_mode;
 	evt->rating = 450;
-	clockevents_config_and_register(evt, clk_rate / (TICK_BASE_CNT + 1),
-					0xf, 0x7fffffff);
 	exynos4_mct_write(TICK_BASE_CNT, mevt->base + MCT_L_TCNTB_OFFSET);
@@ -432,6 +430,8 @@ static int exynos4_local_timer_setup(struct clock_event_device *evt)
 	} else {
 		enable_percpu_irq(mct_irqs[MCT_L0_IRQ], 0);
+	clockevents_config_and_register(evt, clk_rate / (TICK_BASE_CNT + 1),
+					0xf, 0x7fffffff);
 	return 0;

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