Re: [PATCH v2 4/4] cpufreq: Use policy->min/max init as QoS request

From: zhenglifeng (A)

Date: Thu May 21 2026 - 07:28:35 EST


On 5/11/2026 9:55 PM, Pierre Gondois wrote:
> Consider policy->min/max being set in the driver .init()
> callback as a QoS request. Impacted driver are:
> - gx-suspmod.c (min)
> - cppc-cpufreq.c (min)
> - longrun.c (min/max)
>
> Update the documentation accordingly.
>
> Signed-off-by: Pierre Gondois <pierre.gondois@xxxxxxx>
> ---
> Documentation/cpu-freq/cpu-drivers.rst | 10 ++++++++--
> drivers/cpufreq/cpufreq.c | 12 ++++++++++--
> 2 files changed, 18 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/cpu-freq/cpu-drivers.rst b/Documentation/cpu-freq/cpu-drivers.rst
> index c5635ac3de547..ab4f3c0f3a89b 100644
> --- a/Documentation/cpu-freq/cpu-drivers.rst
> +++ b/Documentation/cpu-freq/cpu-drivers.rst
> @@ -114,8 +114,14 @@ Then, the driver must fill in the following values:
> |policy->cur | The current operating frequency of |
> | | this CPU (if appropriate) |
> +-----------------------------------+--------------------------------------+
> -|policy->min, | |
> -|policy->max, | |
> +|policy->min | If set by the driver in ->init(), |
> +| | used as initial minimum frequency |
> +| | QoS request. |
> ++-----------------------------------+--------------------------------------+
> +|policy->max | If set by the driver in ->init(), |
> +| | used as initial maximum frequency |
> +| | QoS request. |
> ++-----------------------------------+--------------------------------------+
> |policy->policy and, if necessary, | |
> |policy->governor | must contain the "default policy" for|
> | | this CPU. A few moments later, |
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index 9e2d9d3fc5351..9a005367ed87b 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -1399,8 +1399,16 @@ static void cpufreq_policy_free(struct cpufreq_policy *policy)
>
> static int cpufreq_policy_init_qos(struct cpufreq_policy *policy)
> {
> + unsigned int min_freq, max_freq;
> int ret;
>
> + /* Use policy->min/max set by the driver as QoS requests. */
> + min_freq = max(FREQ_QOS_MIN_DEFAULT_VALUE, policy->min);
> + if (policy->max)
> + max_freq = min(FREQ_QOS_MAX_DEFAULT_VALUE, policy->max);
> + else
> + max_freq = FREQ_QOS_MAX_DEFAULT_VALUE;
> +

Can't see the point of this. Why not just use policy->max and policy->min
to init qos?

> /*
> * If the driver didn't set policy->min/max, set them as
> * they are used to clamp frequency requests.
> @@ -1418,12 +1426,12 @@ static int cpufreq_policy_init_qos(struct cpufreq_policy *policy)
> }
>
> ret = freq_qos_add_request(&policy->constraints, &policy->min_freq_req,
> - FREQ_QOS_MIN, FREQ_QOS_MIN_DEFAULT_VALUE);
> + FREQ_QOS_MIN, min_freq);
> if (ret < 0)
> return ret;
>
> ret = freq_qos_add_request(&policy->constraints, &policy->max_freq_req,
> - FREQ_QOS_MAX, FREQ_QOS_MAX_DEFAULT_VALUE);
> + FREQ_QOS_MAX, max_freq);
> if (ret < 0)
> return ret;
>