Re: [PATCH] drm/xe/xe_gt_debugfs: Add synchronous gt reset debugfs

[Matthew Brost <matthew.brost@intel.com>]

On Wed, Jun 05, 2024 at 08:08:28AM -0700, Jonathan Cavitt wrote:
> We currently have debugfs support that allows the userspace to initiate
> an asynchronous gt reset on command.  However, userspace may also wish
> to wait for the completion of the gt reset before performing any
> additional work.  To that end, add a version of the force_reset gt
> debugfs function that operates synchronously.
> 
> Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/1068
> Suggested-by: Matthew Brost <matthew.brost@intel.com>

Longterm we may want to switch resets to a single debugfs entry which
accepts a write value and takes actions based on this. I am ok with this
going in but something to keep in mind. 

With that:
Reviewed-by: Matthew Brost <matthew.brost@intel.com>

> Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
> CC: John Harrison <john.c.harrison@intel.com>
> CC: Stuart Summers <stuart.summers@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_gt_debugfs.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_gt_debugfs.c b/drivers/gpu/drm/xe/xe_gt_debugfs.c
> index 66f897a9b6ca9..5e7fd937917a1 100644
> --- a/drivers/gpu/drm/xe/xe_gt_debugfs.c
> +++ b/drivers/gpu/drm/xe/xe_gt_debugfs.c
> @@ -116,6 +116,17 @@ static int force_reset(struct xe_gt *gt, struct drm_printer *p)
>  	return 0;
>  }
>  
> +static int force_reset_sync(struct xe_gt *gt, struct drm_printer *p)
> +{
> +	xe_pm_runtime_get(gt_to_xe(gt));
> +	xe_gt_reset_async(gt);
> +	xe_pm_runtime_put(gt_to_xe(gt));
> +
> +	flush_work(&gt->reset.worker);
> +
> +	return 0;
> +}
> +
>  static int sa_info(struct xe_gt *gt, struct drm_printer *p)
>  {
>  	struct xe_tile *tile = gt_to_tile(gt);
> @@ -261,6 +272,7 @@ static int vecs_default_lrc(struct xe_gt *gt, struct drm_printer *p)
>  static const struct drm_info_list debugfs_list[] = {
>  	{"hw_engines", .show = xe_gt_debugfs_simple_show, .data = hw_engines},
>  	{"force_reset", .show = xe_gt_debugfs_simple_show, .data = force_reset},
> +	{"force_reset_sync", .show = xe_gt_debugfs_simple_show, .data = force_reset_sync},
>  	{"sa_info", .show = xe_gt_debugfs_simple_show, .data = sa_info},
>  	{"topology", .show = xe_gt_debugfs_simple_show, .data = topology},
>  	{"steering", .show = xe_gt_debugfs_simple_show, .data = steering},
> -- 
> 2.25.1
>