[PATCH 3/7] drm/amd/pm: correct the fan speed PWM retrieving

[Lazar, Lijo]

On 7/7/2021 7:26 AM, Evan Quan wrote:
> The relationship "PWM = RPM / smu->fan_max_rpm" between fan speed
> PWM and RPM is not true for SMU11 ASICs. So, we need a new way to
> retrieving the fan speed PWM.
> 
> Change-Id: Idfe0276d7113b9c921b88fa08085a33fd971d621
> Signed-off-by: Evan Quan <evan.quan at amd.com>
> ---
>   .../include/asic_reg/thm/thm_11_0_2_offset.h  |  3 ++
>   .../include/asic_reg/thm/thm_11_0_2_sh_mask.h |  3 ++
>   drivers/gpu/drm/amd/pm/inc/smu_v11_0.h        |  3 ++
>   .../amd/pm/powerplay/hwmgr/vega20_thermal.c   | 24 ++++++++-----
>   .../gpu/drm/amd/pm/swsmu/smu11/arcturus_ppt.c | 25 +------------
>   .../gpu/drm/amd/pm/swsmu/smu11/navi10_ppt.c   | 25 +------------
>   .../amd/pm/swsmu/smu11/sienna_cichlid_ppt.c   | 25 +------------
>   .../gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c    | 35 +++++++++++++++++++
>   8 files changed, 62 insertions(+), 81 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/include/asic_reg/thm/thm_11_0_2_offset.h b/drivers/gpu/drm/amd/include/asic_reg/thm/thm_11_0_2_offset.h
> index a485526f3a51..eca96abef445 100644
> --- a/drivers/gpu/drm/amd/include/asic_reg/thm/thm_11_0_2_offset.h
> +++ b/drivers/gpu/drm/amd/include/asic_reg/thm/thm_11_0_2_offset.h
> @@ -49,4 +49,7 @@
>   #define mmTHM_BACO_CNTL                                                                                0x0081
>   #define mmTHM_BACO_CNTL_BASE_IDX                                                                       0
>   
> +#define mmCG_THERMAL_STATUS                                                                            0x006C
> +#define mmCG_THERMAL_STATUS_BASE_IDX                                                                   0
> +
>   #endif
> diff --git a/drivers/gpu/drm/amd/include/asic_reg/thm/thm_11_0_2_sh_mask.h b/drivers/gpu/drm/amd/include/asic_reg/thm/thm_11_0_2_sh_mask.h
> index d130d92aee19..f2f9eae9a68f 100644
> --- a/drivers/gpu/drm/amd/include/asic_reg/thm/thm_11_0_2_sh_mask.h
> +++ b/drivers/gpu/drm/amd/include/asic_reg/thm/thm_11_0_2_sh_mask.h
> @@ -92,5 +92,8 @@
>   #define THM_TCON_THERM_TRIP__RSVD3_MASK                                                                       0x7FFFC000L
>   #define THM_TCON_THERM_TRIP__SW_THERM_TP_MASK                                                                 0x80000000L
>   
> +#define CG_THERMAL_STATUS__FDO_PWM_DUTY__SHIFT                                                                0x9
> +#define CG_THERMAL_STATUS__FDO_PWM_DUTY_MASK                                                                  0x0001FE00L
> +
>   #endif
>   
> diff --git a/drivers/gpu/drm/amd/pm/inc/smu_v11_0.h b/drivers/gpu/drm/amd/pm/inc/smu_v11_0.h
> index 134a33e3de91..8e0f8e9a1665 100644
> --- a/drivers/gpu/drm/amd/pm/inc/smu_v11_0.h
> +++ b/drivers/gpu/drm/amd/pm/inc/smu_v11_0.h
> @@ -226,6 +226,9 @@ int smu_v11_0_set_fan_speed_percent(struct smu_context *smu,
>   int smu_v11_0_set_fan_speed_rpm(struct smu_context *smu,
>   				uint32_t speed);
>   
> +int smu_v11_0_get_fan_speed_percent(struct smu_context *smu,
> +				    uint32_t *speed);
> +
>   int smu_v11_0_set_xgmi_pstate(struct smu_context *smu,
>   				     uint32_t pstate);
>   
> diff --git a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega20_thermal.c b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega20_thermal.c
> index 269dd7e95a44..43d754952bd9 100644
> --- a/drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega20_thermal.c
> +++ b/drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega20_thermal.c
> @@ -117,18 +117,24 @@ static int vega20_get_current_rpm(struct pp_hwmgr *hwmgr, uint32_t *current_rpm)
>   int vega20_fan_ctrl_get_fan_speed_percent(struct pp_hwmgr *hwmgr,
>   		uint32_t *speed)
>   {
> -	struct vega20_hwmgr *data = (struct vega20_hwmgr *)(hwmgr->backend);
> -	PPTable_t *pp_table = &(data->smc_state_table.pp_table);
> -	uint32_t current_rpm, percent = 0;
> -	int ret = 0;
> +	struct amdgpu_device *adev = hwmgr->adev;
> +	uint32_t duty100, duty;
> +	uint64_t tmp64;
>   
> -	ret = vega20_get_current_rpm(hwmgr, &current_rpm);
> -	if (ret)
> -		return ret;
> +	duty100 = REG_GET_FIELD(RREG32_SOC15(THM, 0, mmCG_FDO_CTRL1),
> +				CG_FDO_CTRL1, FMAX_DUTY100);
> +	duty = REG_GET_FIELD(RREG32_SOC15(THM, 0, mmCG_THERMAL_STATUS),
> +				CG_THERMAL_STATUS, FDO_PWM_DUTY);
> +
> +	if (!duty100)
> +		return -EINVAL;
>   
> -	percent = current_rpm * 100 / pp_table->FanMaximumRpm;
> +	tmp64 = (uint64_t)duty * 100;
> +	do_div(tmp64, duty100);
> +	*speed = (uint32_t)tmp64;
>   
> -	*speed = percent > 100 ? 100 : percent;
> +	if (*speed > 100)
> +		*speed = 100;

Patch 5 avoids conversion as the relation between PWM and RPM is not 
linear. Suggest to return PWM value (0-255) directly instead of 
percentage. Since the function cannot be reused for rpm, it may make 
sense to rename to set/get pwm instead of percent.

Thanks,
Lijo