linux-kernel - [PATCH] clocksource/drivers/riscv: Events are stopped during CPU suspend

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Date:   Sun,  8 May 2022 20:21:21 -0500
From:   Samuel Holland <samuel@...lland.org>
To:     Daniel Lezcano <daniel.lezcano@...aro.org>,
        Thomas Gleixner <tglx@...utronix.de>
Cc:     Samuel Holland <samuel@...lland.org>,
        Albert Ou <aou@...s.berkeley.edu>,
        Atish Patra <atishp@...shpatra.org>,
        Dmitriy Cherkasov <dmitriy@...-tech.org>,
        Palmer Dabbelt <palmer@...belt.com>,
        Paul Walmsley <paul.walmsley@...ive.com>,
        linux-kernel@...r.kernel.org, linux-riscv@...ts.infradead.org
Subject: [PATCH] clocksource/drivers/riscv: Events are stopped during CPU suspend

Some implementations of the SBI time extension depend on hart-local
state (for example, CSRs) that are lost or hardware that is powered
down when a CPU is suspended. To be safe, the clockevents driver
cannot assume that timer IRQs will be received during CPU suspend.

Fixes: 62b019436814 ("clocksource: new RISC-V SBI timer driver")
Signed-off-by: Samuel Holland <samuel@...lland.org>
---

 drivers/clocksource/timer-riscv.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c
index 1767f8bf2013..593d5a957b69 100644
--- a/drivers/clocksource/timer-riscv.c
+++ b/drivers/clocksource/timer-riscv.c
@@ -34,7 +34,7 @@ static int riscv_clock_next_event(unsigned long delta,
 static unsigned int riscv_clock_event_irq;
 static DEFINE_PER_CPU(struct clock_event_device, riscv_clock_event) = {
 	.name			= "riscv_timer_clockevent",
-	.features		= CLOCK_EVT_FEAT_ONESHOT,
+	.features		= CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP,
 	.rating			= 100,
 	.set_next_event		= riscv_clock_next_event,
 };
-- 
2.35.1