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-rw-r--r--drivers/clocksource/timer-stm32.c21
1 files changed, 18 insertions, 3 deletions
diff --git a/drivers/clocksource/timer-stm32.c b/drivers/clocksource/timer-stm32.c
index dcf844598230..4ce234500258 100644
--- a/drivers/clocksource/timer-stm32.c
+++ b/drivers/clocksource/timer-stm32.c
@@ -101,7 +101,15 @@ static void stm32_clock_event_disable(struct timer_of *to)
writel_relaxed(0, timer_of_base(to) + TIM_DIER);
}
-static void stm32_clock_event_enable(struct timer_of *to)
+/**
+ * stm32_timer_start - Start the counter without event
+ * @to: a timer_of structure pointer
+ *
+ * Start the timer in order to have the counter reset and start
+ * incrementing but disable interrupt event when there is a counter
+ * overflow. By default, the counter direction is used as upcounter.
+ */
+static void stm32_timer_start(struct timer_of *to)
{
writel_relaxed(TIM_CR1_UDIS | TIM_CR1_CEN, timer_of_base(to) + TIM_CR1);
}
@@ -137,7 +145,7 @@ static int stm32_clock_event_set_periodic(struct clock_event_device *clkevt)
{
struct timer_of *to = to_timer_of(clkevt);
- stm32_clock_event_enable(to);
+ stm32_timer_start(to);
return stm32_clock_event_set_next_event(timer_of_period(to), clkevt);
}
@@ -146,7 +154,7 @@ static int stm32_clock_event_set_oneshot(struct clock_event_device *clkevt)
{
struct timer_of *to = to_timer_of(clkevt);
- stm32_clock_event_enable(to);
+ stm32_timer_start(to);
return 0;
}
@@ -235,6 +243,13 @@ static int __init stm32_clocksource_init(struct timer_of *to)
* sched_clock.
*/
if (bits == 32 && !stm32_timer_cnt) {
+
+ /*
+ * Start immediately the counter as we will be using
+ * it right after.
+ */
+ stm32_timer_start(to);
+
stm32_timer_cnt = timer_of_base(to) + TIM_CNT;
sched_clock_register(stm32_read_sched_clock, bits, timer_of_rate(to));
pr_info("%s: STM32 sched_clock registered\n", name);