Re: [PATCH 1/2] drm/xe: Avoid memory allocations in xe_device_declare_wedged()

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Thu, Mar 26, 2026 at 02:01:15PM -0700, Matthew Brost wrote:
> xe_device_declare_wedged() runs in the DMA-fence signaling path, where
> GFP_KERNEL memory allocations are not allowed. However, registering
> xe_device_wedged_fini via drmm_add_action_or_reset() triggers a
> GFP_KERNEL allocation.
> 
> Fix this by deferring the registration of xe_device_wedged_fini until
> late in the driver load sequence. Additionally, drop the wedged PM
> reference only if the device is actually wedged in
> xe_device_wedged_fini.
> 
> Fixes: ("452bca0edbd0 drm/xe: Don't suspend device upon wedge")
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

> ---
>  drivers/gpu/drm/xe/xe_device.c | 27 +++++++++++++--------------
>  1 file changed, 13 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
> index 9b0540e3e289..ffea4a453c01 100644
> --- a/drivers/gpu/drm/xe/xe_device.c
> +++ b/drivers/gpu/drm/xe/xe_device.c
> @@ -833,6 +833,14 @@ static void detect_preproduction_hw(struct xe_device *xe)
>  	}
>  }
>  
> +static void xe_device_wedged_fini(struct drm_device *drm, void *arg)
> +{
> +	struct xe_device *xe = arg;
> +
> +	if (atomic_read(&xe->wedged.flag))
> +		xe_pm_runtime_put(xe);
> +}
> +
>  int xe_device_probe(struct xe_device *xe)
>  {
>  	struct xe_tile *tile;
> @@ -1009,6 +1017,10 @@ int xe_device_probe(struct xe_device *xe)
>  
>  	detect_preproduction_hw(xe);
>  
> +	err = drmm_add_action_or_reset(&xe->drm, xe_device_wedged_fini, xe);
> +	if (err)
> +		goto err_unregister_display;
> +
>  	return devm_add_action_or_reset(xe->drm.dev, xe_device_sanitize, xe);
>  
>  err_unregister_display:
> @@ -1240,13 +1252,6 @@ u64 xe_device_uncanonicalize_addr(struct xe_device *xe, u64 address)
>  	return address & GENMASK_ULL(xe->info.va_bits - 1, 0);
>  }
>  
> -static void xe_device_wedged_fini(struct drm_device *drm, void *arg)
> -{
> -	struct xe_device *xe = arg;
> -
> -	xe_pm_runtime_put(xe);
> -}
> -
>  /**
>   * DOC: Xe Device Wedging
>   *
> @@ -1324,15 +1329,9 @@ void xe_device_declare_wedged(struct xe_device *xe)
>  		return;
>  	}
>  
> -	xe_pm_runtime_get_noresume(xe);
> -
> -	if (drmm_add_action_or_reset(&xe->drm, xe_device_wedged_fini, xe)) {
> -		drm_err(&xe->drm, "Failed to register xe_device_wedged_fini clean-up. Although device is wedged.\n");
> -		return;
> -	}
> -
>  	if (!atomic_xchg(&xe->wedged.flag, 1)) {
>  		xe->needs_flr_on_fini = true;
> +		xe_pm_runtime_get_noresume(xe);
>  		drm_err(&xe->drm,
>  			"CRITICAL: Xe has declared device %s as wedged.\n"
>  			"IOCTLs and executions are blocked.\n"
> -- 
> 2.34.1
>