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From: Zide Chen <zide.chen@intel.com>
To: Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Namhyung Kim <namhyung@kernel.org>,
	Ian Rogers <irogers@google.com>,
	Adrian Hunter <adrian.hunter@intel.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Andi Kleen <ak@linux.intel.com>,
	Eranian Stephane <eranian@google.com>
Cc: linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
	Dapeng Mi <dapeng1.mi@linux.intel.com>,
	Zide Chen <zide.chen@intel.com>,
	stable@vger.kernel.org
Subject: [PATCH V2 4/7] perf/x86/intel/uncore: Defer ADL global PMON enable to enable_box()
Date: Wed, 27 May 2026 08:11:51 -0700	[thread overview]
Message-ID: <20260527151154.130505-4-zide.chen@intel.com> (raw)
In-Reply-To: <20260527151154.130505-1-zide.chen@intel.com>

On some Raptor Cove CPUs, enabling uncore PMON globally at driver init
may increase power consumption even when no perf events are in use.

Drop adl_uncore_msr_init_box() and defer programming the global control
register to enable_box(), so it is only set when a box is actually used.

IMC and IMC freerunning counters use a separate control path and are
unaffected.

Cc: stable@vger.kernel.org
Signed-off-by: Zide Chen <zide.chen@intel.com>
---
 arch/x86/events/intel/uncore_snb.c | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/arch/x86/events/intel/uncore_snb.c b/arch/x86/events/intel/uncore_snb.c
index 3dbc6bacbd9d..edddd4f9ab5f 100644
--- a/arch/x86/events/intel/uncore_snb.c
+++ b/arch/x86/events/intel/uncore_snb.c
@@ -563,12 +563,6 @@ void tgl_uncore_cpu_init(void)
 	skl_uncore_msr_ops.init_box = rkl_uncore_msr_init_box;
 }
 
-static void adl_uncore_msr_init_box(struct intel_uncore_box *box)
-{
-	if (box->pmu->pmu_idx == 0)
-		wrmsrq(ADL_UNC_PERF_GLOBAL_CTL, SNB_UNC_GLOBAL_CTL_EN);
-}
-
 static void adl_uncore_msr_enable_box(struct intel_uncore_box *box)
 {
 	wrmsrq(ADL_UNC_PERF_GLOBAL_CTL, SNB_UNC_GLOBAL_CTL_EN);
@@ -587,7 +581,6 @@ static void adl_uncore_msr_exit_box(struct intel_uncore_box *box)
 }
 
 static struct intel_uncore_ops adl_uncore_msr_ops = {
-	.init_box	= adl_uncore_msr_init_box,
 	.enable_box	= adl_uncore_msr_enable_box,
 	.disable_box	= adl_uncore_msr_disable_box,
 	.exit_box	= adl_uncore_msr_exit_box,
-- 
2.54.0


       reply	other threads:[~2026-05-27 15:20 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20260527151154.130505-1-zide.chen@intel.com>
2026-05-27 15:11 ` Zide Chen [this message]
2026-05-28  6:35   ` [PATCH V2 4/7] perf/x86/intel/uncore: Defer ADL global PMON enable to enable_box() Mi, Dapeng
2026-05-28 18:07     ` Chen, Zide

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