Re: [PATCH v2 1/2] drm/xe/gt: Synchronize GT reset with device unbind

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

On Thu, Oct 30, 2025 at 08:41:24PM +0530, Balasubramani Vivekanandan wrote:
> When unbinding wait for any GT reset in progress to complete. Unbinding
> will release the mmio mapping but mmio operations are performed during
> GT reset causing Kernel panic.
> 
> Cc: Lucas De Marchi <lucas.demarchi@intel.com>
> Signed-off-by: Balasubramani Vivekanandan <balasubramani.vivekanandan@intel.com>
> ---
> v2:
>  - Use the managed resource release function to wait for GT reset during
>    unbind (Lucas)
> ---
>  drivers/gpu/drm/xe/xe_gt.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_gt.c b/drivers/gpu/drm/xe/xe_gt.c
> index 89808b33d0a8..d0f8c40bc51e 100644
> --- a/drivers/gpu/drm/xe/xe_gt.c
> +++ b/drivers/gpu/drm/xe/xe_gt.c
> @@ -607,6 +607,8 @@ static void xe_gt_fini(void *arg)
>  	struct xe_gt *gt = arg;
>  	int i;
>  
> +	disable_work_sync(&gt->reset.worker);

We recently made a change [1] so if GT reset worker is queued it holds a PM ref.

So if disable_work_sync returns true [2], I think a PM ref needs to be dropped here.

Matt

[1] https://patchwork.freedesktop.org/patch/682622/?series=156292&rev=1
[2] https://elixir.bootlin.com/linux/v6.17.6/source/kernel/workqueue.c#L4471

>
>  	for (i = 0; i < XE_ENGINE_CLASS_MAX; ++i)
>  		xe_hw_fence_irq_finish(&gt->fence_irq[i]);
>  
> -- 
> 2.43.0
>