[PATCH] drm/amd/powerplay: use work queue to perform throttling logging

[Nirmoy]

LGTM

Acked-by: Nirmoy Das <nirmoy.das at amd.com>

On 6/3/20 7:03 AM, Evan Quan wrote:
> As IO operations(access to SMU internals) and possible sleep are
> involved in throttling logging. Workqueue can handle them well.
> Otherwise we may hit "scheduling while atomic" error.
>
> Change-Id: I454d593e965e54b13fdf04c112abb0a022204278
> Signed-off-by: Evan Quan <evan.quan at amd.com>
> ---
>   drivers/gpu/drm/amd/powerplay/amdgpu_smu.c     | 10 ++++++++++
>   drivers/gpu/drm/amd/powerplay/inc/amdgpu_smu.h |  2 ++
>   drivers/gpu/drm/amd/powerplay/smu_v11_0.c      |  2 +-
>   3 files changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/powerplay/amdgpu_smu.c b/drivers/gpu/drm/amd/powerplay/amdgpu_smu.c
> index 342fd75b0806..e25a3b1ce7ac 100644
> --- a/drivers/gpu/drm/amd/powerplay/amdgpu_smu.c
> +++ b/drivers/gpu/drm/amd/powerplay/amdgpu_smu.c
> @@ -1053,6 +1053,14 @@ static int smu_smc_table_sw_fini(struct smu_context *smu)
>   	return 0;
>   }
>   
> +static void smu_throttling_logging_work_fn(struct work_struct *work)
> +{
> +	struct smu_context *smu = container_of(work, struct smu_context,
> +					       throttling_logging_work);
> +
> +	smu_log_thermal_throttling(smu);
> +}
> +
>   static int smu_sw_init(void *handle)
>   {
>   	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
> @@ -1074,6 +1082,7 @@ static int smu_sw_init(void *handle)
>   	spin_lock_init(&smu->metrics_lock);
>   	spin_lock_init(&smu->message_lock);
>   
> +	INIT_WORK(&smu->throttling_logging_work, smu_throttling_logging_work_fn);
>   	smu->watermarks_bitmap = 0;
>   	smu->power_profile_mode = PP_SMC_POWER_PROFILE_BOOTUP_DEFAULT;
>   	smu->default_power_profile_mode = PP_SMC_POWER_PROFILE_BOOTUP_DEFAULT;
> @@ -1295,6 +1304,7 @@ static int smu_internal_hw_cleanup(struct smu_context *smu)
>   
>   	smu_i2c_eeprom_fini(smu, &adev->pm.smu_i2c);
>   
> +	cancel_work_sync(&smu->throttling_logging_work);
>   	ret = smu_disable_thermal_alert(smu);
>   	if (ret) {
>   		pr_warn("Fail to stop thermal control!\n");
> diff --git a/drivers/gpu/drm/amd/powerplay/inc/amdgpu_smu.h b/drivers/gpu/drm/amd/powerplay/inc/amdgpu_smu.h
> index 6f44ffb6eb51..b970b4d663b0 100644
> --- a/drivers/gpu/drm/amd/powerplay/inc/amdgpu_smu.h
> +++ b/drivers/gpu/drm/amd/powerplay/inc/amdgpu_smu.h
> @@ -411,6 +411,8 @@ struct smu_context
>   
>   	bool uploading_custom_pp_table;
>   	bool dc_controlled_by_gpio;
> +
> +	struct work_struct throttling_logging_work;
>   };
>   
>   struct i2c_adapter;
> diff --git a/drivers/gpu/drm/amd/powerplay/smu_v11_0.c b/drivers/gpu/drm/amd/powerplay/smu_v11_0.c
> index adde9eb7b283..69b1160d8ba2 100644
> --- a/drivers/gpu/drm/amd/powerplay/smu_v11_0.c
> +++ b/drivers/gpu/drm/amd/powerplay/smu_v11_0.c
> @@ -1597,7 +1597,7 @@ static int smu_v11_0_irq_process(struct amdgpu_device *adev,
>   					return 0;
>   
>   				if (__ratelimit(&adev->throttling_logging_rs))
> -					smu_log_thermal_throttling(smu);
> +					schedule_work(&smu->throttling_logging_work);
>   
>   				break;
>   			}