drm/panfrost: Use DRM_GPU_SCHED_STAT_NO_HANG to skip the reset

Panfrost can skip the reset if TDR has fired before the free-job worker.
Currently, since Panfrost doesn't take any action on these scenarios, the
job is being leaked, considering that `free_job()` won't be called.

To avoid such leaks, inform the scheduler that the job did not actually
timeout and no reset was performed through the new status code
DRM_GPU_SCHED_STAT_NO_HANG.

Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20250714-sched-skip-reset-v6-8-5c5ba4f55039@igalia.com
Signed-off-by: Maíra Canal <mcanal@igalia.com>

Author: mairacanal

drivers/gpu/drm/panfrost/panfrost_job.c

@@ -751,11 +751,11 @@ static enum drm_gpu_sched_stat panfrost_job_timedout(struct drm_sched_job
 	int js = panfrost_job_get_slot(job);
 
 	/*
-	 * If the GPU managed to complete this jobs fence, the timeout is
-	 * spurious. Bail out.
+	 * If the GPU managed to complete this jobs fence, the timeout has
+	 * fired before free-job worker. The timeout is spurious, so bail out.
 	 */
 	if (dma_fence_is_signaled(job->done_fence))
-		return DRM_GPU_SCHED_STAT_RESET;
+		return DRM_GPU_SCHED_STAT_NO_HANG;
 
 	/*
 	 * Panfrost IRQ handler may take a long time to process an interrupt
@@ -770,7 +770,7 @@ static enum drm_gpu_sched_stat panfrost_job_timedout(struct drm_sched_job
 
 	if (dma_fence_is_signaled(job->done_fence)) {
 		dev_warn(pfdev->dev, "unexpectedly high interrupt latency\n");
-		return DRM_GPU_SCHED_STAT_RESET;
+		return DRM_GPU_SCHED_STAT_NO_HANG;
 	}
 
 	dev_err(pfdev->dev, "gpu sched timeout, js=%d, config=0x%x, status=0x%x, head=0x%x, tail=0x%x, sched_job=%p",