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

[Michal Wajdeczko <michal.wajdeczko@intel.com>]

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

> 
> 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 ?

> +
> +		*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

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
>