[PATCH 1/2] drm/amd/amdgpu: enable clockgating only after late init

[Christian König]

Am 07.10.2016 um 20:50 schrieb Alex Deucher:
> From: Arindam Nath <arindam.nath at amd.com>
>
> Sometimes during multiple reboots, the system hangs
> during bootup. The issue is very random and happens
> once in around 50 reboots or so.
>
> It seems if clockgating is enabled before late init,
> the GFX engine sometimes does not respond.
>
> This patch changes the ordering a little so that
> both powergating and clockgating are enabled only
> after late init calls.
>
> Signed-off-by: Arindam Nath <arindam.nath at amd.com>
> Tested-by: Sunil Uttarwar <Sunil.Uttarwar1 at amd.com>
> Reviewed-by: Tom St Denis <tom.stdenis at amd.com>
> Reviewed-by: Alex Deucher <alexander.deucher at amd.com>
> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>

For patch #2 I suggest that we clean up those things in the long run 
with some sort of per IP flags instead of checking the type directly.

But for now that should be sufficient and both patches are Reviewed-by: 
Christian König <christian.koenig at amd.com>.

Christian.

> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 14 +++++++-------
>   1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index 575a84b..e43779f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -1437,13 +1437,6 @@ static int amdgpu_late_init(struct amdgpu_device *adev)
>   		if (adev->ip_blocks[i].type == AMD_IP_BLOCK_TYPE_UVD ||
>   			adev->ip_blocks[i].type == AMD_IP_BLOCK_TYPE_VCE)
>   			continue;
> -		/* enable clockgating to save power */
> -		r = adev->ip_blocks[i].funcs->set_clockgating_state((void *)adev,
> -								    AMD_CG_STATE_GATE);
> -		if (r) {
> -			DRM_ERROR("set_clockgating_state(gate) of IP block <%s> failed %d\n", adev->ip_blocks[i].funcs->name, r);
> -			return r;
> -		}
>   		if (adev->ip_blocks[i].funcs->late_init) {
>   			r = adev->ip_blocks[i].funcs->late_init((void *)adev);
>   			if (r) {
> @@ -1452,6 +1445,13 @@ static int amdgpu_late_init(struct amdgpu_device *adev)
>   			}
>   			adev->ip_block_status[i].late_initialized = true;
>   		}
> +		/* enable clockgating to save power */
> +		r = adev->ip_blocks[i].funcs->set_clockgating_state((void *)adev,
> +								    AMD_CG_STATE_GATE);
> +		if (r) {
> +			DRM_ERROR("set_clockgating_state(gate) of IP block <%s> failed %d\n", adev->ip_blocks[i].funcs->name, r);
> +			return r;
> +		}
>   	}
>   
>   	return 0;