Re: [PATCH v2] cpufreq: apple-soc: Calculate frequency as a 64-bit value

[Janne Grunau]

On Mon, Jul 20, 2026 at 09:25:10AM +0200, Sasha Finkelstein wrote:
> The current frequency calculation is done in 32 bit, causing problems
> if run on a future SoC that can boost higher than 4.2GHz. Ideally, we
> should use a true u64 instead of unsigned long and "knowning" that this
> only runs on 64 bit machines, but the core code uses ulong everywhere,
> so this should be good enough.

It depends on 'ARCH_APPLE || (COMPILE_TEST && 64BIT)' so it only gets
built for 64-bit architectures so the unsigned long won't cause compiler
warnings/errors.

> Signed-off-by: Sasha Finkelstein <k@xxxxxxxxxxxxxx>
> ---
> Changes in v2:
> - Minor style fixes
> - Link to v1: https://patch.msgid.link/20260703-cpufreq-64-v1-1-c406c705319a@xxxxxxxxxxxxxx
> ---
>  drivers/cpufreq/apple-soc-cpufreq.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/cpufreq/apple-soc-cpufreq.c b/drivers/cpufreq/apple-soc-cpufreq.c
> index 638e5bf72185..5ad274a1e6ae 100644
> --- a/drivers/cpufreq/apple-soc-cpufreq.c
> +++ b/drivers/cpufreq/apple-soc-cpufreq.c
> @@ -288,7 +288,7 @@ static int apple_soc_cpufreq_init(struct cpufreq_policy *policy)
>  
>  	/* Get OPP levels (p-state indexes) and stash them in driver_data */
>  	for (i = 0; freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
> -		unsigned long rate = freq_table[i].frequency * 1000 + 999;
> +		unsigned long rate = freq_table[i].frequency * 1000UL + 999;
>  		struct dev_pm_opp *opp = dev_pm_opp_find_freq_floor(cpu_dev, &rate);
>  
>  		if (IS_ERR(opp)) {
> 

Reviewed-by: Janne Grunau <j@xxxxxxxxxx>

Janne