linux-kernel - [PATCH v19 06/11] perf: apple_m1: Don't disable counter in m1_pmu_enable

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Message-Id: <20250202-arm-brbe-v19-v19-6-1c1300802385@kernel.org>
Date: Sun, 02 Feb 2025 18:43:00 -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 06/11] perf: apple_m1: Don't disable counter in
 m1_pmu_enable_event()

Currently m1_pmu_enable_event() starts 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
m1_pmu_enable_event() is called.

Cc: Marc Zyngier <maz@...nel.org>
Signed-off-by: Rob Herring (Arm) <robh@...nel.org>
---
 drivers/perf/apple_m1_cpu_pmu.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/perf/apple_m1_cpu_pmu.c b/drivers/perf/apple_m1_cpu_pmu.c
index 06fd317529fc..39349ecec3c1 100644
--- a/drivers/perf/apple_m1_cpu_pmu.c
+++ b/drivers/perf/apple_m1_cpu_pmu.c
@@ -396,10 +396,6 @@ static void m1_pmu_enable_event(struct perf_event *event)
 	user = event->hw.config_base & M1_PMU_CFG_COUNT_USER;
 	kernel = event->hw.config_base & M1_PMU_CFG_COUNT_KERNEL;
 
-	m1_pmu_disable_counter_interrupt(event->hw.idx);
-	m1_pmu_disable_counter(event->hw.idx);
-	isb();
-
 	m1_pmu_configure_counter(event->hw.idx, evt, user, kernel);
 	m1_pmu_enable_counter(event->hw.idx);
 	m1_pmu_enable_counter_interrupt(event->hw.idx);

-- 
2.47.2