linux-kernel - [PATCH 5/7] perf: arm_v7_pmu: Don't disable counter in (armv7|krait_|scorpion_)pmu_enable

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Message-Id: <20250107-arm-pmu-cleanups-v1-v1-5-313951346a25@kernel.org>
Date: Tue, 07 Jan 2025 11:57:23 -0600
From: "Rob Herring (Arm)" <robh@...nel.org>
To: Will Deacon <will@...nel.org>, Mark Rutland <mark.rutland@....com>
Cc: Marc Zyngier <maz@...nel.org>, linux-arm-kernel@...ts.infradead.org, 
 linux-kernel@...r.kernel.org
Subject: [PATCH 5/7] 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 7fa88e3b64e07bacbf2f9731e3318a7dc1085fb1..17831e1920bd8d306aa1ea9cebe8b3f4659dfcee 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

-- 
2.45.2