Re: [PATCH v1] cpufreq: intel_pstate: Skip HWP_CAP reads in Broadwell mode

[srinivas pandruvada]

On Fri, 2026-06-19 at 21:24 +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> 
> When running in the Broadwell HWP mode, the turbo, max and min
> P-state values are retrieved from MSR_PLATFORM_INFO, so reading
> MSR_HWP_CAPABILITIES in that mode in order to update those values
> is pointless.  Moreover, using the MSR_HWP_CAPABILITIES value for
> updating them in the Broadwell mode may be harmful, so avoid doing
> that altogether.
> 
> Fixes: de5bcf404ace ("cpufreq: intel_pstate: Clean up frequency
> computations")


Can't apply this patch on the latest Linux master even after applying
prior 6 patches.
What is this based on?

Thanks,
Srinivas

> Link:
> https://sashiko.dev/#/patchset/6005456.DvuYhMxLoT%40rafael.j.wysocki
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> Cc: All applicable <stable@xxxxxxxxxxxxxxx>
> ---
>  drivers/cpufreq/intel_pstate.c |    3 +++
>  1 file changed, 3 insertions(+)
> 
> --- a/drivers/cpufreq/intel_pstate.c
> +++ b/drivers/cpufreq/intel_pstate.c
> @@ -1197,6 +1197,9 @@ static void intel_pstate_get_hwp_cap(str
>  {
>  	int scaling = cpu->pstate.scaling;
>  
> +	if (hwp_mode_bdw)
> +		return;
> +
>  	__intel_pstate_get_hwp_cap(cpu);
>  
>  	cpu->pstate.max_freq = cpu->pstate.max_pstate * scaling;
> 
> 
>