Re: [PATCH 08/14] drm/i915/guc/slpc: Add get max/min freq hooks

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

On 7/21/2021 11:00 AM, Michal Wajdeczko wrote:
> 
> 
> On 21.07.2021 18:11, Vinay Belgaumkar wrote:
>> Add helpers to read the min/max frequency being used
>> by SLPC. This is done by send a H2G command which forces
>> SLPC to update the shared data struct which can then be
>> read.
> 
> add note that functions will be used later

ok.

> 
>>
>> v2: Address review comments (Michal W)
>>
>> Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
>> Signed-off-by: Sundaresan Sujaritha <sujaritha.sundaresan@intel.com>
>> ---
>>   drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c | 52 +++++++++++++++++++++
>>   drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.h |  2 +
>>   2 files changed, 54 insertions(+)
>>
>> 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 b40c39ba4049..c1cf8d46e360 100644
>> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c
>> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c
>> @@ -290,6 +290,32 @@ int intel_guc_slpc_set_max_freq(struct intel_guc_slpc *slpc, u32 val)
>>   	return ret;
>>   }
>>   
>> +/**
>> + * intel_guc_slpc_get_max_freq() - Get max frequency limit for SLPC.
>> + * @slpc: pointer to intel_guc_slpc.
>> + * @val: pointer to val which will hold max frequency (MHz)
>> + *
>> + * This function will invoke GuC SLPC action to read the max frequency
>> + * limit for unslice.
>> + *
>> + * Return: 0 on success, non-zero error code on failure.
>> + */
>> +int intel_guc_slpc_get_max_freq(struct intel_guc_slpc *slpc, u32 *val)
>> +{
>> +	intel_wakeref_t wakeref;
>> +	struct drm_i915_private *i915 = guc_to_gt(slpc_to_guc(slpc))->i915;
>> +	int ret = 0;
> 
> struct drm_i915_private *i915 = slpc_to_i915(slpc);
> intel_wakeref_t wakeref;
> int ret = 0;
> 
>> +
>> +	with_intel_runtime_pm(&i915->runtime_pm, wakeref) {
>> +		/* Force GuC to update task data */
>> +		slpc_query_task_state(slpc);
> 
> what if this call fails ?

saving error in ret.

> 
>> +
>> +		*val = slpc_decode_max_freq(slpc);
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>>   /**
>>    * intel_guc_slpc_set_min_freq() - Set min frequency limit for SLPC.
>>    * @slpc: pointer to intel_guc_slpc.
>> @@ -322,6 +348,32 @@ int intel_guc_slpc_set_min_freq(struct intel_guc_slpc *slpc, u32 val)
>>   	return ret;
>>   }
>>   
>> +/**
>> + * intel_guc_slpc_get_min_freq() - Get min frequency limit for SLPC.
>> + * @slpc: pointer to intel_guc_slpc.
>> + * @val: pointer to val which will hold min frequency (MHz)
>> + *
>> + * This function will invoke GuC SLPC action to read the min frequency
>> + * limit for unslice.
>> + *
>> + * Return: 0 on success, non-zero error code on failure.
>> + */
>> +int intel_guc_slpc_get_min_freq(struct intel_guc_slpc *slpc, u32 *val)
>> +{
>> +	intel_wakeref_t wakeref;
>> +	struct drm_i915_private *i915 = guc_to_gt(slpc_to_guc(slpc))->i915;
>> +	int ret = 0;
>> +
>> +	with_intel_runtime_pm(&i915->runtime_pm, wakeref) {
>> +		/* Force GuC to update task data */
>> +		slpc_query_task_state(slpc);
> 
> same here

Populated ret with return code.

Thanks,
Vinay.
> 
> Michal
> 
>> +
>> +		*val = slpc_decode_min_freq(slpc);
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>>   /*
>>    * intel_guc_slpc_enable() - Start SLPC
>>    * @slpc: pointer to intel_guc_slpc.
>> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.h b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.h
>> index 3a1a7eaafc12..627c71a95777 100644
>> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.h
>> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.h
>> @@ -32,5 +32,7 @@ int intel_guc_slpc_enable(struct intel_guc_slpc *slpc);
>>   void intel_guc_slpc_fini(struct intel_guc_slpc *slpc);
>>   int intel_guc_slpc_set_max_freq(struct intel_guc_slpc *slpc, u32 val);
>>   int intel_guc_slpc_set_min_freq(struct intel_guc_slpc *slpc, u32 val);
>> +int intel_guc_slpc_get_max_freq(struct intel_guc_slpc *slpc, u32 *val);
>> +int intel_guc_slpc_get_min_freq(struct intel_guc_slpc *slpc, u32 *val);
>>   
>>   #endif
>>