[PATCH v2] drm/amdgpu: fix CG enabling hang with gfxoff enabled

[Christian König]

Am 05.06.2018 um 05:01 schrieb Huang Rui:
> After defer the execution of clockgating enabling, at that time, gfx already
> enter into "off" state. Howerver, clockgating enabling will use MMIO to access
> the gfx registers, then get the gfx hung.
>
> So here we should move the gfx powergating and gfxoff enabling behavior at the
> end of initialization behind clockgating.
>
> Signed-off-by: Huang Rui <ray.huang at amd.com>
> Cc: Hawking Zhang <Hawking.Zhang at amd.com>
> Cc: Felix Kuehling <Felix.Kuehling at amd.com>
> Cc: Christian König <christian.koenig at amd.com>

Acked-by: Christian König <christian.koenig at amd.com>

Thanks for the patience figuring out the real root cause,
Christian.

> ---
>
> Changes from V1 -> V2:
> - Update real root cause of gfx hung with gfxoff enabled.
>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c        | 12 ++++++++++++
>   drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c             |  5 -----
>   drivers/gpu/drm/amd/powerplay/amd_powerplay.c     |  2 +-
>   drivers/gpu/drm/amd/powerplay/hwmgr/smu10_hwmgr.c |  4 ++--
>   4 files changed, 15 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index f509d32..72b95f7 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -1723,6 +1723,18 @@ static int amdgpu_device_ip_late_set_cg_state(struct amdgpu_device *adev)
>   			}
>   		}
>   	}
> +
> +	if (adev->powerplay.pp_feature & PP_GFXOFF_MASK) {
> +		/* enable gfx powergating */
> +		amdgpu_device_ip_set_powergating_state(adev,
> +						       AMD_IP_BLOCK_TYPE_GFX,
> +						       AMD_CG_STATE_GATE);
> +		/* enable gfxoff */
> +		amdgpu_device_ip_set_powergating_state(adev,
> +						       AMD_IP_BLOCK_TYPE_SMC,
> +						       AMD_CG_STATE_GATE);
> +	}
> +
>   	return 0;
>   }
>   
> diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> index 2c5e2a4..31ecc86 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c
> @@ -3358,11 +3358,6 @@ static int gfx_v9_0_late_init(void *handle)
>   	if (r)
>   		return r;
>   
> -	r = amdgpu_device_ip_set_powergating_state(adev, AMD_IP_BLOCK_TYPE_GFX,
> -						   AMD_PG_STATE_GATE);
> -	if (r)
> -		return r;
> -
>   	return 0;
>   }
>   
> diff --git a/drivers/gpu/drm/amd/powerplay/amd_powerplay.c b/drivers/gpu/drm/amd/powerplay/amd_powerplay.c
> index b493369..d0e6e2d 100644
> --- a/drivers/gpu/drm/amd/powerplay/amd_powerplay.c
> +++ b/drivers/gpu/drm/amd/powerplay/amd_powerplay.c
> @@ -245,7 +245,7 @@ static int pp_set_powergating_state(void *handle,
>   	}
>   
>   	if (hwmgr->hwmgr_func->enable_per_cu_power_gating == NULL) {
> -		pr_info("%s was not implemented.\n", __func__);
> +		pr_debug("%s was not implemented.\n", __func__);
>   		return 0;
>   	}
>   
> diff --git a/drivers/gpu/drm/amd/powerplay/hwmgr/smu10_hwmgr.c b/drivers/gpu/drm/amd/powerplay/hwmgr/smu10_hwmgr.c
> index 7712eb6..b72d089 100644
> --- a/drivers/gpu/drm/amd/powerplay/hwmgr/smu10_hwmgr.c
> +++ b/drivers/gpu/drm/amd/powerplay/hwmgr/smu10_hwmgr.c
> @@ -284,7 +284,7 @@ static int smu10_disable_gfx_off(struct pp_hwmgr *hwmgr)
>   
>   static int smu10_disable_dpm_tasks(struct pp_hwmgr *hwmgr)
>   {
> -	return smu10_disable_gfx_off(hwmgr);
> +	return 0;
>   }
>   
>   static int smu10_enable_gfx_off(struct pp_hwmgr *hwmgr)
> @@ -299,7 +299,7 @@ static int smu10_enable_gfx_off(struct pp_hwmgr *hwmgr)
>   
>   static int smu10_enable_dpm_tasks(struct pp_hwmgr *hwmgr)
>   {
> -	return smu10_enable_gfx_off(hwmgr);
> +	return 0;
>   }
>   
>   static int smu10_gfx_off_control(struct pp_hwmgr *hwmgr, bool enable)