Re: [PATCH v3] drm/xe/uc: Add stop on hardware initialization error

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

On Tue, Oct 28, 2025 at 11:38:20AM -0400, Zhanjun Dong wrote:
> On hardware init fail, the hardware might no longer response, add GuC stop
> to clean up exec_queue items.
> 
> Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/5466
> Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/5530
> Signed-off-by: Zhanjun Dong <zhanjun.dong@intel.com>
> ---
> v3: Switch to xe_guc_stop
> v2: Switch to xe_guc_ct_stop
> ---
>  drivers/gpu/drm/xe/xe_uc.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_uc.c b/drivers/gpu/drm/xe/xe_uc.c
> index 465bda355443..00ca5883e006 100644
> --- a/drivers/gpu/drm/xe/xe_uc.c
> +++ b/drivers/gpu/drm/xe/xe_uc.c
> @@ -173,6 +173,7 @@ static int vf_uc_load_hw(struct xe_uc *uc)
>  	return 0;
>  
>  err_out:
> +	xe_guc_stop(&uc->guc);

If exec queues are destroyed later—after the submission backend has been
stopped—the final put on the queue may be lost, leading to dangling
memory when aborting the driver load or unloading it.

I think you'll need to call xe_guc_submit_pause_abort somewhere to
ensure the final put cleanup messages are processed by the queues. Maybe
we add this call in guc_submit_fini before wait_event_timeout?

Matt

>  	xe_guc_sanitize(&uc->guc);
>  	return err;
>  }
> @@ -228,6 +229,7 @@ int xe_uc_load_hw(struct xe_uc *uc)
>  	return 0;
>  
>  err_out:
> +	xe_guc_stop(&uc->guc);
>  	xe_guc_sanitize(&uc->guc);
>  	return ret;
>  }
> -- 
> 2.34.1
>