[PATCH v2] clocksource: timer-riscv: Clear timer interrupt on timer initialization

From: Ley Foon Tan
Date: Mon Jan 29 2024 - 02:42:50 EST


In the RISC-V specification, the stimecmp register doesn't have a default
value. To prevent the timer interrupt from being triggered during timer
initialization, clear the timer interrupt by writing stimecmp with a
maximum value.

Fixes: 9f7a8ff6391f ("RISC-V: Prefer sstc extension if available")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Ley Foon Tan <leyfoon.tan@xxxxxxxxxxxxxxxx>

---
v2:
Resolved comments from Anup.
- Moved riscv_clock_event_stop() to riscv_timer_starting_cpu().
- Added Fixes tag
---
drivers/clocksource/timer-riscv.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c
index e66dcbd66566..672669eb7281 100644
--- a/drivers/clocksource/timer-riscv.c
+++ b/drivers/clocksource/timer-riscv.c
@@ -116,6 +116,9 @@ static int riscv_timer_starting_cpu(unsigned int cpu)
ce->rating = 450;
clockevents_config_and_register(ce, riscv_timebase, 100, 0x7fffffff);

+ /* Clear timer interrupt */
+ riscv_clock_event_stop();
+
enable_percpu_irq(riscv_clock_event_irq,
irq_get_trigger_type(riscv_clock_event_irq));
return 0;
--
2.43.0