linux-kernel - [PATCH v19 05/11] perf: arm_v7_pmu: Don't disable counter in (armv7|krait_|scorpion_)pmu_enable

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Message-Id: <20250202-arm-brbe-v19-v19-5-1c1300802385@kernel.org>
Date: Sun, 02 Feb 2025 18:42:59 -0600
From: "Rob Herring (Arm)" <robh@...nel.org>
To: Will Deacon <will@...nel.org>, Mark Rutland <mark.rutland@....com>, 
 Catalin Marinas <catalin.marinas@....com>, Jonathan Corbet <corbet@....net>, 
 Marc Zyngier <maz@...nel.org>, Oliver Upton <oliver.upton@...ux.dev>, 
 Joey Gouly <joey.gouly@....com>, Suzuki K Poulose <suzuki.poulose@....com>, 
 Zenghui Yu <yuzenghui@...wei.com>, James Clark <james.clark@...aro.org>, 
 Anshuman Khandual <anshuman.khandual@....com>
Cc: linux-arm-kernel@...ts.infradead.org, linux-perf-users@...r.kernel.org, 
 linux-kernel@...r.kernel.org, linux-doc@...r.kernel.org, 
 kvmarm@...ts.linux.dev
Subject: [PATCH v19 05/11] perf: arm_v7_pmu: Don't disable counter in
 (armv7|krait_|scorpion_)pmu_enable_event()

Currently (armv7|krait_|scorpion_)pmu_enable_event() start by disabling
the event counter it has been asked to enable. This should not be
necessary as the counter (and the PMU as a whole) should not be active
when *_enable_event() is called.

Signed-off-by: Rob Herring (Arm) <robh@...nel.org>
---
 drivers/perf/arm_v7_pmu.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/perf/arm_v7_pmu.c b/drivers/perf/arm_v7_pmu.c
index 7fa88e3b64e0..17831e1920bd 100644
--- a/drivers/perf/arm_v7_pmu.c
+++ b/drivers/perf/arm_v7_pmu.c
@@ -857,8 +857,6 @@ static void armv7pmu_enable_event(struct perf_event *event)
 		return;
 	}
 
-	armv7_pmnc_disable_counter(idx);
-
 	/*
 	 * Set event (if destined for PMNx counters)
 	 * We only need to set the event for the cycle counter if we
@@ -1450,8 +1448,6 @@ static void krait_pmu_enable_event(struct perf_event *event)
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = hwc->idx;
 
-	armv7_pmnc_disable_counter(idx);
-
 	/*
 	 * Set event (if destined for PMNx counters)
 	 * We set the event for the cycle counter because we
@@ -1762,8 +1758,6 @@ static void scorpion_pmu_enable_event(struct perf_event *event)
 	struct hw_perf_event *hwc = &event->hw;
 	int idx = hwc->idx;
 
-	armv7_pmnc_disable_counter(idx);
-
 	/*
 	 * Set event (if destined for PMNx counters)
 	 * We don't set the event for the cycle counter because we

-- 
2.47.2