[PART1 PATCH v2 7/8] drm/amdgpu: add get clockgating_state method for uvd v5&v6

[Christian König]

Am 06.01.2017 um 08:45 schrieb Huang Rui:
> Signed-off-by: Huang Rui <ray.huang at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu.h   |  1 +
>   drivers/gpu/drm/amd/amdgpu/uvd_v5_0.c | 26 ++++++++++++++++++++++++--
>   drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c | 26 ++++++++++++++++++++++++--
>   3 files changed, 49 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index 530549b..31054c7 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -1183,6 +1183,7 @@ struct amdgpu_uvd {
>   	bool			use_ctx_buf;
>   	struct amd_sched_entity entity;
>   	uint32_t                srbm_soft_reset;
> +	bool			is_powergated;
>   };
>   
>   /*
> diff --git a/drivers/gpu/drm/amd/amdgpu/uvd_v5_0.c b/drivers/gpu/drm/amd/amdgpu/uvd_v5_0.c
> index 03a35d9..ca96f06 100644
> --- a/drivers/gpu/drm/amd/amdgpu/uvd_v5_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/uvd_v5_0.c
> @@ -781,16 +781,37 @@ static int uvd_v5_0_set_powergating_state(void *handle,
>   	 * the smc and the hw blocks
>   	 */
>   	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
> +	int ret;
>   
>   	if (!(adev->pg_flags & AMD_PG_SUPPORT_UVD))
>   		return 0;
>   
>   	if (state == AMD_PG_STATE_GATE) {
> +		adev->uvd.is_powergated = true;
>   		uvd_v5_0_stop(adev);
> -		return 0;
>   	} else {
> -		return uvd_v5_0_start(adev);
> +		ret = uvd_v5_0_start(adev);
> +		if (ret)
> +			return ret;
> +		adev->uvd.is_powergated = false;
> +	}
> +	return 0;
> +}
> +
> +static void uvd_v5_0_get_clockgating_state(void *handle, u32 *flags)
> +{
> +	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
> +	int data;
> +
> +	if (adev->uvd.is_powergated) {
> +		DRM_INFO("Cannot get clockgating state when UVD is powergated.\n");
> +		return;
>   	}
> +
> +	/* AMD_CG_SUPPORT_UVD_MGCG */
> +	data = RREG32(mmUVD_CGC_CTRL);
> +	if (data & UVD_CGC_CTRL__DYN_CLOCK_MODE_MASK)
> +		*flags |= AMD_CG_SUPPORT_UVD_MGCG;
>   }
>   
>   static const struct amd_ip_funcs uvd_v5_0_ip_funcs = {
> @@ -808,6 +829,7 @@ static const struct amd_ip_funcs uvd_v5_0_ip_funcs = {
>   	.soft_reset = uvd_v5_0_soft_reset,
>   	.set_clockgating_state = uvd_v5_0_set_clockgating_state,
>   	.set_powergating_state = uvd_v5_0_set_powergating_state,
> +	.get_clockgating_state = uvd_v5_0_get_clockgating_state,
>   };
>   
>   static const struct amdgpu_ring_funcs uvd_v5_0_ring_funcs = {
> diff --git a/drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c b/drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c
> index 8779d4b..0ce6a11 100644
> --- a/drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/uvd_v6_0.c
> @@ -987,6 +987,7 @@ static int uvd_v6_0_set_powergating_state(void *handle,
>   	 * the smc and the hw blocks
>   	 */
>   	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
> +	int ret;
>   
>   	if (!(adev->pg_flags & AMD_PG_SUPPORT_UVD))
>   		return 0;
> @@ -994,11 +995,31 @@ static int uvd_v6_0_set_powergating_state(void *handle,
>   	WREG32(mmUVD_POWER_STATUS, UVD_POWER_STATUS__UVD_PG_EN_MASK);
>   
>   	if (state == AMD_PG_STATE_GATE) {
> +		adev->uvd.is_powergated = true;
>   		uvd_v6_0_stop(adev);
> -		return 0;
>   	} else {
> -		return uvd_v6_0_start(adev);
> +		ret = uvd_v6_0_start(adev);
> +		if (ret)
> +			return ret;
> +		adev->uvd.is_powergated = false;
> +	}
> +	return 0;
> +}
> +
> +static void uvd_v6_0_get_clockgating_state(void *handle, u32 *flags)
> +{
> +	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
> +	int data;
> +
> +	if (adev->uvd.is_powergated) {
> +		DRM_INFO("Cannot get clockgating state when UVD is powergated.\n");
> +		return;
>   	}

This is not really save. The power can be gated just in the moment you 
check the variable.

Adding a spinlock or mutex to protect the variable should be sufficient.

Regards,
Christian.

> +
> +	/* AMD_CG_SUPPORT_UVD_MGCG */
> +	data = RREG32(mmUVD_CGC_CTRL);
> +	if (data & UVD_CGC_CTRL__DYN_CLOCK_MODE_MASK)
> +		*flags |= AMD_CG_SUPPORT_UVD_MGCG;
>   }
>   
>   static const struct amd_ip_funcs uvd_v6_0_ip_funcs = {
> @@ -1019,6 +1040,7 @@ static const struct amd_ip_funcs uvd_v6_0_ip_funcs = {
>   	.post_soft_reset = uvd_v6_0_post_soft_reset,
>   	.set_clockgating_state = uvd_v6_0_set_clockgating_state,
>   	.set_powergating_state = uvd_v6_0_set_powergating_state,
> +	.get_clockgating_state = uvd_v6_0_get_clockgating_state,
>   };
>   
>   static const struct amdgpu_ring_funcs uvd_v6_0_ring_phys_funcs = {