Re: [PATCH] drm/i915/slpc: Update min_freq_softlimit when ignore_eff_freq is enabled

["Belgaumkar, Vinay" <vinay.belgaumkar@intel.com>]

On 9/9/2025 11:22 PM, Anirban, Sk wrote:
> Hi,
>
> On 10-09-2025 04:07, Belgaumkar, Vinay wrote:
>>
>> On 9/9/2025 6:28 AM, Sk Anirban wrote:
>>> When slpc_ignore_eff_freq is enabled, min frequency is set to RPn but
>>> min_freq_softlimit is not updated, causing sysfs to show stale
>>> values.
>>
>> sysfs(get_min_freq) does a query_task_state and then displays the min 
>> freq. That shouldn't be stale info. Within slpc code, we are using 
>> min_freq_softlimit to track user changes to min freq. We shouldn't be 
>> overwriting this when efficient freq is toggled.
>>
>> Thanks,
>>
>> Vinay.
> While fetching min_freq, we currently return slpc->min_freq_softlimit 
> from intel_rps_get_min_frequency. However, if the internal minimum 
> frequency has been updated to RPn, imo this change should be reflected 
> to the user as well.

Are you seeing an issue with this? min_freq_softlimit is initialized to 
RPn afaics. So, changing min_freq to RPn when we disable RPe should not 
affect anything.

Thanks,

Vinay.

>
> Thanks,
> Anirban
>>
>>>
>>> Update min freq softlimit when ignore_eff_freq is successfully enabled.
>>>
>>> Signed-off-by: Sk Anirban <sk.anirban@intel.com>
>>> ---
>>>   drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c | 5 ++++-
>>>   1 file changed, 4 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c 
>>> b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c
>>> index d5ee6e5e1443..07fa0423b1a3 100644
>>> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c
>>> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c
>>> @@ -495,10 +495,13 @@ int intel_guc_slpc_set_ignore_eff_freq(struct 
>>> intel_guc_slpc *slpc, bool val)
>>>           slpc->ignore_eff_freq = val;
>>>             /* Set min to RPn when we disable efficient freq */
>>> -        if (val)
>>> +        if (val) {
>>>               ret = slpc_set_param(slpc,
>>> SLPC_PARAM_GLOBAL_MIN_GT_UNSLICE_FREQ_MHZ,
>>>                            slpc->min_freq);
>>> +            if (!ret)
>>> +                slpc->min_freq_softlimit = slpc->min_freq;
>>> +        }
>>>       }
>>>         intel_runtime_pm_put(&i915->runtime_pm, wakeref);
>