Re: [PATCH] drm/amd/pm: Fix incorrect avg vcn utilization in gpu_metrics

[Boqun Feng <boqun@kernel.org>]

On Wed, Aug 05, 2026 at 07:02:21AM -0700, Boqun Feng wrote:
> In a Strix Halo system, a >100 average_vcn_activity in gpu_metrics can
> be observed by running the following command:
> 
>     ffmpeg -hwaccel vappi -vappi_device /dev/dri/renderD128 -i \
>     ~/sample-10s.mp4 -vf hwupload,scale_vappi=format=nv12 -c:v \
>     h264_vappi /tmp/output.mp4
> 
> This is incorrect because the value is supposed to be in [0-100] range.
> 
> The cause of the issue is that the metrics.VcnActivity reported by
> smu_cmn_get_metrics_table() is a permyriad value instead of a percentage
> value (e.g. smu_v14_0_0_get_smu_metrics_data() has a division by 100 to
> report the vcn_busy_percent). Therefore fix this by applying the same
> division in smu_v14_0_0_get_gpu_metrics().
> 
> Reported-by: Mark Janes <mjanes@netflix.com>
> Signed-off-by: Boqun Feng <boqun@kernel.org>

Ping?

Regards,
Boqun

> ---
>  drivers/gpu/drm/amd/pm/swsmu/smu14/smu_v14_0_0_ppt.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu14/smu_v14_0_0_ppt.c b/drivers/gpu/drm/amd/pm/swsmu/smu14/smu_v14_0_0_ppt.c
> index 568665265a13..1058338344b0 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/smu14/smu_v14_0_0_ppt.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/smu14/smu_v14_0_0_ppt.c
> @@ -566,7 +566,8 @@ static ssize_t smu_v14_0_0_get_gpu_metrics(struct smu_context *smu,
>  	gpu_metrics->temperature_skin = metrics.SkinTemp;
>  
>  	gpu_metrics->average_gfx_activity = metrics.GfxActivity;
> -	gpu_metrics->average_vcn_activity = metrics.VcnActivity;
> +	/* metrics.VcnActivity is permyriad, convert it to percentage. */
> +	gpu_metrics->average_vcn_activity = metrics.VcnActivity / 100;
>  	memcpy(&gpu_metrics->average_ipu_activity[0],
>  		&metrics.IpuBusy[0],
>  		sizeof(uint16_t) * 8);
> -- 
> 2.50.1 (Apple Git-155)
>