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

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

[Sasha Finkelstein]

The current frequency calculation is done in 32 bit, causing problems
if run on a future SoC that can boost higher than 4.2GHz.

Signed-off-by: Sasha Finkelstein <k@chaosmail.tech>
---
 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..6a0f1d36578f 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 + 999UL;
 		struct dev_pm_opp *opp = dev_pm_opp_find_freq_floor(cpu_dev, &rate);
 
 		if (IS_ERR(opp)) {

---
base-commit: 4a50a141f05a8d1737661b19ee22ff8455b94409
change-id: 20260703-cpufreq-64-2a23d7261e09

Best regards,
--  
Sasha Finkelstein <k@chaosmail.tech>

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

[David Laight]

On Fri, 03 Jul 2026 20:52:48 +0200
Sasha Finkelstein <k@chaosmail.tech> 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.

If it matters you need to fix it for 32bit builds as well.
It is pretty much really wrong to use 'unsigned long' for frequencies.
IMHO the should either be 32bit or 64bit.

	David

> 
> Signed-off-by: Sasha Finkelstein <k@chaosmail.tech>
> ---
>  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..6a0f1d36578f 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 + 999UL;
>  		struct dev_pm_opp *opp = dev_pm_opp_find_freq_floor(cpu_dev, &rate);
>  
>  		if (IS_ERR(opp)) {
> 
> ---
> base-commit: 4a50a141f05a8d1737661b19ee22ff8455b94409
> change-id: 20260703-cpufreq-64-2a23d7261e09
> 
> Best regards,
> --  
> Sasha Finkelstein <k@chaosmail.tech>
> 
> 

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

[Sasha Finkelstein]

On Jul 3, 2026, at 22:52, David Laight <david.laight.linux@gmail.com> wrote:
> 
> If it matters you need to fix it for 32bit builds as well.
> It is pretty much really wrong to use 'unsigned long' for frequencies.
> IMHO the should either be 32bit or 64bit.

This module has a 64BIT dep, and is not applicable to 32-bit devices.
In addition, the calculation is passed to dev_pm_opp_find_freq_floor,
which is core code and takes an unsigned long.