linux-kernel - [PATCH 7/9] clockevents/drivers/arm_arch_timer: Implement ->set_state_oneshot

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Date:	Thu, 25 Feb 2016 14:37:15 +0100
From:	Daniel Lezcano <daniel.lezcano@...aro.org>
To:	tglx@...utronix.de
Cc:	Viresh Kumar <viresh.kumar@...aro.org>,
	linux-kernel@...r.kernel.org (open list:CLOCKSOURCE, CLOC...)
Subject: [PATCH 7/9] clockevents/drivers/arm_arch_timer: Implement ->set_state_oneshot_stopped()

From: Viresh Kumar <viresh.kumar@...aro.org>

set_state_oneshot_stopped() is called by the clkevt core, when the next
event is required at an expiry time of 'KTIME_MAX'. This normally
happens with NO_HZ_{IDLE|FULL} in both LOWRES/HIGHRES modes.

This patch makes the clockevent device to stop on such an event, to
avoid spurious interrupts, as explained by: commit 8fff52fd5093
("clockevents: Introduce CLOCK_EVT_STATE_ONESHOT_STOPPED state").

Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@...aro.org>
---
 drivers/clocksource/arm_arch_timer.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 7c567f0..f0dd9d4 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -274,10 +274,12 @@ static void __arch_timer_setup(unsigned type,
 		if (arch_timer_use_virtual) {
 			clk->irq = arch_timer_ppi[VIRT_PPI];
 			clk->set_state_shutdown = arch_timer_shutdown_virt;
+			clk->set_state_oneshot_stopped = arch_timer_shutdown_virt;
 			clk->set_next_event = arch_timer_set_next_event_virt;
 		} else {
 			clk->irq = arch_timer_ppi[PHYS_SECURE_PPI];
 			clk->set_state_shutdown = arch_timer_shutdown_phys;
+			clk->set_state_oneshot_stopped = arch_timer_shutdown_phys;
 			clk->set_next_event = arch_timer_set_next_event_phys;
 		}
 	} else {
@@ -287,10 +289,12 @@ static void __arch_timer_setup(unsigned type,
 		clk->cpumask = cpu_all_mask;
 		if (arch_timer_mem_use_virtual) {
 			clk->set_state_shutdown = arch_timer_shutdown_virt_mem;
+			clk->set_state_oneshot_stopped = arch_timer_shutdown_virt_mem;
 			clk->set_next_event =
 				arch_timer_set_next_event_virt_mem;
 		} else {
 			clk->set_state_shutdown = arch_timer_shutdown_phys_mem;
+			clk->set_state_oneshot_stopped = arch_timer_shutdown_phys_mem;
 			clk->set_next_event =
 				arch_timer_set_next_event_phys_mem;
 		}
-- 
1.9.1