Re: [PATCH v2 2/3] drm/xe: Allow the pm notifier to continue on failure

[Matthew Auld <matthew.auld@intel.com>]

On 01/09/2025 09:38, Thomas Hellström wrote:
> Its actions are opportunistic anyway and will be completed
> on device suspend.

If it fails here, it will likely also fail in the real suspend part 
which is more hostile/restrictive environment, so maybe failing early is 
better? Not completely sure though.

Reviewed-by: Matthew Auld <matthew.auld@intel.com>

> 
> Marking as a fix to simplify backporting of the fix
> that follows in the series.
> 
> v2:
> - Keep the runtime pm reference over suspend / hibernate and
>    document why. (Matt Auld, Rodrigo Vivi):
> 
> Fixes: c6a4d46ec1d7 ("drm/xe: evict user memory in PM notifier")
> Cc: Matthew Auld <matthew.auld@intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Cc: <stable@vger.kernel.org> # v6.16+
> Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> ---
>   drivers/gpu/drm/xe/xe_pm.c | 17 +++++++----------
>   1 file changed, 7 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c
> index a2e85030b7f4..bee9aacd82e7 100644
> --- a/drivers/gpu/drm/xe/xe_pm.c
> +++ b/drivers/gpu/drm/xe/xe_pm.c
> @@ -308,17 +308,17 @@ static int xe_pm_notifier_callback(struct notifier_block *nb,
>   	case PM_SUSPEND_PREPARE:
>   		xe_pm_runtime_get(xe);
>   		err = xe_bo_evict_all_user(xe);
> -		if (err) {
> +		if (err)
>   			drm_dbg(&xe->drm, "Notifier evict user failed (%d)\n", err);
> -			xe_pm_runtime_put(xe);
> -			break;
> -		}
>   
>   		err = xe_bo_notifier_prepare_all_pinned(xe);
> -		if (err) {
> +		if (err)
>   			drm_dbg(&xe->drm, "Notifier prepare pin failed (%d)\n", err);
> -			xe_pm_runtime_put(xe);
> -		}
> +		/*
> +		 * Keep the runtime pm reference until post hibernation / post suspend to
> +		 * avoid a runtime suspend interfering with evicted objects or backup
> +		 * allocations.
> +		 */
>   		break;
>   	case PM_POST_HIBERNATION:
>   	case PM_POST_SUSPEND:
> @@ -327,9 +327,6 @@ static int xe_pm_notifier_callback(struct notifier_block *nb,
>   		break;
>   	}
>   
> -	if (err)
> -		return NOTIFY_BAD;
> -
>   	return NOTIFY_DONE;
>   }
>