linux-kernel - [PATCH v2 kvm-riscv/for-next 1/2] drivers/perf: riscv: Remove the warning from stop function

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Message-Id: <20240426031637.4135544-2-atishp@rivosinc.com>
Date: Thu, 25 Apr 2024 20:16:36 -0700
From: Atish Patra <atishp@...osinc.com>
To: linux-kernel@...r.kernel.org
Cc: Atish Patra <atishp@...osinc.com>,
	Samuel Holland <samuel.holland@...ive.com>,
	Albert Ou <aou@...s.berkeley.edu>,
	Alexandre Ghiti <alexghiti@...osinc.com>,
	Andrew Jones <ajones@...tanamicro.com>,
	Anup Patel <anup@...infault.org>,
	Atish Patra <atishp@...shpatra.org>,
	Conor Dooley <conor.dooley@...rochip.com>,
	linux-riscv@...ts.infradead.org,
	kvm-riscv@...ts.infradead.org,
	Mark Rutland <mark.rutland@....com>,
	Palmer Dabbelt <palmer@...belt.com>,
	Paul Walmsley <paul.walmsley@...ive.com>,
	Will Deacon <will@...nel.org>
Subject: [PATCH v2 kvm-riscv/for-next 1/2] drivers/perf: riscv: Remove the warning from stop function

The warning message was initially added just to indicate that counter
stop function is being called while the event is already stopped.

However, we update the state to stopped case now in an overflow handler
after stopping the counter. If there is another child overflow handler
is registered (e.g kvm) it may call stop again which will trigger the
warning.

Fixes: 22f5dac41004 ("drivers/perf: riscv: Implement SBI PMU snapshot function")

Reviewed-by: Samuel Holland <samuel.holland@...ive.com>
Signed-off-by: Atish Patra <atishp@...osinc.com>
---
 drivers/perf/riscv_pmu.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/perf/riscv_pmu.c b/drivers/perf/riscv_pmu.c
index 36d348753d05..78c490e0505a 100644
--- a/drivers/perf/riscv_pmu.c
+++ b/drivers/perf/riscv_pmu.c
@@ -191,8 +191,6 @@ void riscv_pmu_stop(struct perf_event *event, int flags)
 	struct hw_perf_event *hwc = &event->hw;
 	struct riscv_pmu *rvpmu = to_riscv_pmu(event->pmu);
 
-	WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
-
 	if (!(hwc->state & PERF_HES_STOPPED)) {
 		if (rvpmu->ctr_stop) {
 			rvpmu->ctr_stop(event, 0);
-- 
2.34.1