[PATCH] drm/amdgpu/smu: add a send message lock

[Nirmoy]

On 2/18/20 3:31 PM, Alex Deucher wrote:
> The driver uses a scratch register to communicate with the SMU.
> Add a lock to make sure we don't try and do this concurrently
> by accident.
>
> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
Acked-by: Nirmoy Das <nirmoy.das at amd.com>
> ---
>   drivers/gpu/drm/amd/powerplay/amdgpu_smu.c     | 1 +
>   drivers/gpu/drm/amd/powerplay/inc/amdgpu_smu.h | 1 +
>   drivers/gpu/drm/amd/powerplay/smu_v11_0.c      | 7 ++++++-
>   drivers/gpu/drm/amd/powerplay/smu_v12_0.c      | 7 ++++++-
>   4 files changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/powerplay/amdgpu_smu.c b/drivers/gpu/drm/amd/powerplay/amdgpu_smu.c
> index 437a3e7b36b4..694017740186 100644
> --- a/drivers/gpu/drm/amd/powerplay/amdgpu_smu.c
> +++ b/drivers/gpu/drm/amd/powerplay/amdgpu_smu.c
> @@ -905,6 +905,7 @@ static int smu_sw_init(void *handle)
>   	mutex_init(&smu->sensor_lock);
>   	mutex_init(&smu->metrics_lock);
>   	mutex_init(&smu->update_table_lock);
> +	mutex_init(&smu->send_msg_lock);
>   
>   	smu->watermarks_bitmap = 0;
>   	smu->power_profile_mode = PP_SMC_POWER_PROFILE_BOOTUP_DEFAULT;
> diff --git a/drivers/gpu/drm/amd/powerplay/inc/amdgpu_smu.h b/drivers/gpu/drm/amd/powerplay/inc/amdgpu_smu.h
> index 506288072e8e..25fa5c5ed09b 100644
> --- a/drivers/gpu/drm/amd/powerplay/inc/amdgpu_smu.h
> +++ b/drivers/gpu/drm/amd/powerplay/inc/amdgpu_smu.h
> @@ -363,6 +363,7 @@ struct smu_context
>   	struct mutex			sensor_lock;
>   	struct mutex			metrics_lock;
>   	struct mutex			update_table_lock;
> +	struct mutex			send_msg_lock;
>   	uint64_t pool_size;
>   
>   	struct smu_table_context	smu_table;
> diff --git a/drivers/gpu/drm/amd/powerplay/smu_v11_0.c b/drivers/gpu/drm/amd/powerplay/smu_v11_0.c
> index b06c057a9002..ed5b3afcab66 100644
> --- a/drivers/gpu/drm/amd/powerplay/smu_v11_0.c
> +++ b/drivers/gpu/drm/amd/powerplay/smu_v11_0.c
> @@ -97,12 +97,16 @@ smu_v11_0_send_msg_with_param(struct smu_context *smu,
>   	struct amdgpu_device *adev = smu->adev;
>   	int ret = 0, index = 0;
>   
> +	mutex_lock(&smu->send_msg_lock);
>   	index = smu_msg_get_index(smu, msg);
> -	if (index < 0)
> +	if (index < 0) {
> +		mutex_unlock(&smu->send_msg_lock);
>   		return index;
> +	}
>   
>   	ret = smu_v11_0_wait_for_response(smu);
>   	if (ret) {
> +		mutex_unlock(&smu->send_msg_lock);
>   		pr_err("Msg issuing pre-check failed and "
>   		       "SMU may be not in the right state!\n");
>   		return ret;
> @@ -118,6 +122,7 @@ smu_v11_0_send_msg_with_param(struct smu_context *smu,
>   	if (ret)
>   		pr_err("failed send message: %10s (%d) \tparam: 0x%08x response %#x\n",
>   		       smu_get_message_name(smu, msg), index, param, ret);
> +	mutex_unlock(&smu->send_msg_lock);
>   
>   	return ret;
>   }
> diff --git a/drivers/gpu/drm/amd/powerplay/smu_v12_0.c b/drivers/gpu/drm/amd/powerplay/smu_v12_0.c
> index 870e6db2907e..1ca8a8c959b1 100644
> --- a/drivers/gpu/drm/amd/powerplay/smu_v12_0.c
> +++ b/drivers/gpu/drm/amd/powerplay/smu_v12_0.c
> @@ -83,12 +83,16 @@ smu_v12_0_send_msg_with_param(struct smu_context *smu,
>   	struct amdgpu_device *adev = smu->adev;
>   	int ret = 0, index = 0;
>   
> +	mutex_lock(&smu->send_msg_lock);
>   	index = smu_msg_get_index(smu, msg);
> -	if (index < 0)
> +	if (index < 0) {
> +		mutex_unlock(&smu->send_msg_lock);
>   		return index;
> +	}
>   
>   	ret = smu_v12_0_wait_for_response(smu);
>   	if (ret) {
> +		mutex_unlock(&smu->send_msg_lock);
>   		pr_err("Msg issuing pre-check failed and "
>   		       "SMU may be not in the right state!\n");
>   		return ret;
> @@ -104,6 +108,7 @@ smu_v12_0_send_msg_with_param(struct smu_context *smu,
>   	if (ret)
>   		pr_err("Failed to send message 0x%x, response 0x%x param 0x%x\n",
>   		       index, ret, param);
> +	mutex_unlock(&smu->send_msg_lock);
>   
>   	return ret;
>   }