Re: [PATCH v3 2/4] cpufreq: CPPC: Avoid using CPUFREQ_ETERNAL as transition delay

[Jie Zhan]

On 9/26/2025 6:19 PM, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> 
> If cppc_get_transition_latency() returns CPUFREQ_ETERNAL to indicate a
> failure to retrieve the transition latency value from the platform
> firmware, the CPPC cpufreq driver will use that value (converted to
> microseconds) as the policy transition delay, but it is way too large
> for any practical use.
> 
> Address this by making the driver use the cpufreq's default
> transition latency value (in microseconds) as the transition delay
> if CPUFREQ_ETERNAL is returned by cppc_get_transition_latency().
> 
> Fixes: d4f3388afd48 ("cpufreq / CPPC: Set platform specific transition_delay_us")
> Cc: 5.19+ <stable@xxxxxxxxxxxxxxx> # 5.19
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> Reviewed-by: Mario Limonciello (AMD) <superm1@xxxxxxxxxx>
Reviewed-by: Jie Zhan <zhanjie9@xxxxxxxxxxxxx>
> ---
> 
> v1 -> v3:
>    * Change the name of the new function (Jie Zhan)
>    * Add a tag from Mario Limonciello
> 
> ---
>  drivers/cpufreq/cppc_cpufreq.c |   14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)