[PATCH v2] drm/amdgpu: Poweroff uvd/vce/vcn/acp block if they were disabled by user

[Zhu, Rex]

> -----Original Message-----
> From: Christian König <ckoenig.leichtzumerken at gmail.com>
> Sent: Wednesday, October 17, 2018 2:31 AM
> To: Zhu, Rex <Rex.Zhu at amd.com>; amd-gfx at lists.freedesktop.org
> Subject: Re: [PATCH v2] drm/amdgpu: Poweroff uvd/vce/vcn/acp block if
> they were disabled by user
> 
> Am 16.10.2018 um 20:25 schrieb Rex Zhu:
> > If user disable uvd/vce/vcn/acp blocks via module parameter
> > ip_block_mask, driver power off thoser blocks to save power.
> >
> > v2: power off uvd/vce/vcn/acp via smu.
> 
> I'm not sure if that is a good idea.
> 
> The meaning of the flag is to NOT touch the blocks at all, e.g. pretend they
> don't even exists.
> 
> Additional to that the ip_block_mask is only for bringup and debugging and
> not meant for production use and power saving shouldn't be an issue there.

Hi Christian,

This is requested by Chrome project. As there is an S3 issue caused by VCE, and they still don't find the root cause.
And in Chrome project, they don't need to use vce engine.
So as a workaround, they want to disable vce and power off the vce engine to save power.

Best Regards
Rex
 
> So I would rather say that this is a NAK.
> 
> Christian.
> 
> >
> > Reviewed-by: Alex Deucher <alexander.deucher at amd.com>
> > Signed-off-by: Rex Zhu <Rex.Zhu at amd.com>
> > ---
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 19
> +++++++++++++++++++
> >   1 file changed, 19 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> > index 6fe6ea9..ef9fe50 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> > @@ -1776,6 +1776,24 @@ static int amdgpu_device_set_pg_state(struct
> > amdgpu_device *adev, enum amd_power
> >
> >   	for (j = 0; j < adev->num_ip_blocks; j++) {
> >   		i = state == AMD_PG_STATE_GATE ? j : adev->num_ip_blocks
> - j - 1;
> > +
> > +		/* try to power off VCE/UVD/VCN/ACP if they were disabled
> by user */
> > +		if ((adev->ip_blocks[i].version->type ==
> AMD_IP_BLOCK_TYPE_UVD ||
> > +		    adev->ip_blocks[i].version->type ==
> AMD_IP_BLOCK_TYPE_VCE ||
> > +		    adev->ip_blocks[i].version->type ==
> AMD_IP_BLOCK_TYPE_VCN ||
> > +		    adev->ip_blocks[i].version->type ==
> AMD_IP_BLOCK_TYPE_ACP) &&
> > +		    adev->powerplay.pp_funcs->set_powergating_by_smu) {
> > +			if (!adev->ip_blocks[i].status.valid) {
> > +
> 	amdgpu_dpm_set_powergating_by_smu(adev, adev-
> >ip_blocks[i].version->type, state == AMD_PG_STATE_GATE ?
> > +
> 					true : false);
> > +				if (r) {
> > +
> 	DRM_ERROR("set_powergating_state(gate) of IP block <%s>
> failed %d\n",
> > +					  adev->ip_blocks[i].version->funcs-
> >name, r);
> > +					return r;
> > +				}
> > +			}
> > +		}
> > +
> >   		if (!adev->ip_blocks[i].status.late_initialized)
> >   			continue;
> >   		/* skip CG for VCE/UVD, it's handled specially */ @@ -1793,6
> > +1811,7 @@ static int amdgpu_device_set_pg_state(struct amdgpu_device
> *adev, enum amd_power
> >   			}
> >   		}
> >   	}
> > +
> >   	return 0;
> >   }
> >