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

["Mi, Dapeng" <dapeng1.mi@linux.intel.com>]

On 5/27/2026 11:11 PM, Zide Chen wrote:
> 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

Need a "Fixes" tag?

Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com>


> 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,