[PATCH V2 4/7] perf/x86/intel/uncore: Defer ADL global PMON enable to enable_box()

From: Zide Chen

Date: Wed May 27 2026 - 11:26:19 EST


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@xxxxxxxxxxxxxxx
Signed-off-by: Zide Chen <zide.chen@xxxxxxxxx>
---
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