[PATCH 2/2] drm/xe: Ensure GT reset is complete during ccs_mode change

[Matthew Brost]

On Thu, Nov 14, 2024 at 07:07:38PM +0530, Balasubramani Vivekanandan wrote:
> Driver returns from the ccs_mode change request soon after initiating an
> asynchronous GT reset. Userspace may submit GT workload while the GT
> reset is ongoing and may see unexpected results.

I missed this part. It should be fine to submit a workload while a GT
reset is ongoing. Can you describe the unexpected results because AFIAK
this should work.

Matt

> Make sure the GT reset is complete before exiting from the ccs_mode
> change request.
> 
> Signed-off-by: Balasubramani Vivekanandan <balasubramani.vivekanandan at intel.com>
> ---
>  drivers/gpu/drm/xe/xe_gt_ccs_mode.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_gt_ccs_mode.c b/drivers/gpu/drm/xe/xe_gt_ccs_mode.c
> index b6adfb9f2030..9b6c15239487 100644
> --- a/drivers/gpu/drm/xe/xe_gt_ccs_mode.c
> +++ b/drivers/gpu/drm/xe/xe_gt_ccs_mode.c
> @@ -150,7 +150,7 @@ ccs_mode_store(struct device *kdev, struct device_attribute *attr,
>  		xe_gt_info(gt, "Setting compute mode to %d\n", num_engines);
>  		gt->ccs_mode = num_engines;
>  		xe_gt_record_user_engines(gt);
> -		xe_gt_reset_async(gt);
> +		xe_gt_reset_sync(gt);
>  	}
>  
>  	mutex_unlock(&xe->drm.filelist_mutex);
> -- 
> 2.34.1
>