Re: [PATCH] thermal: intel: powerclamp: Do not log an error on unsupported CPUs

[Rafael J. Wysocki (Intel)]

On Tue, Nov 10, 2026 at 4:30 PM Breno Leitao <leitao@xxxxxxxxxx> wrote:
>
> powerclamp_probe() returns -ENODEV unless x86_match_cpu() finds an
> Intel CPU with MWAIT, and logs "CPU does not support MWAIT" at KERN_ERR
> when it does not.
>
> As a result, a kernel with CONFIG_INTEL_POWERCLAMP=y logs this error on
> every boot on a non-Intel CPU.
>
>   # grep -m1 vendor_id /proc/cpuinfo
>   vendor_id     : AuthenticAMD
>   # grep -m1 -o -w monitor /proc/cpuinfo
>   monitor
>   # dmesg -l err | grep intel_powerclamp:
>   [    0.485728] intel_powerclamp: CPU does not support MWAIT
>
> At KERN_ERR the line also gets past "quiet" and lands on the console,
> and on kernel metrics.
>
> Reduce it to debug, and also name both conditions in the message.
>
> Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>
> ---
>  drivers/thermal/intel/intel_powerclamp.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/thermal/intel/intel_powerclamp.c b/drivers/thermal/intel/intel_powerclamp.c
> index 1ffcb0a699e57d..82587dc8b0156f 100644
> --- a/drivers/thermal/intel/intel_powerclamp.c
> +++ b/drivers/thermal/intel/intel_powerclamp.c
> @@ -695,7 +695,7 @@ static int __init powerclamp_probe(void)
>  {
>
>         if (!x86_match_cpu(intel_powerclamp_ids)) {
> -               pr_err("CPU does not support MWAIT\n");
> +               pr_debug("CPU is not Intel or does not support MWAIT\n");
>                 return -ENODEV;
>         }
>
>
> ---

Applied as 7.5 material, thanks!