drm/panfrost: Handle job HW submit errors

Avoid waiting for the DRM scheduler job timedout handler, and instead, let
the DRM scheduler core signal the error fence immediately when HW job
submission fails.

That means we must also decrement the runtime-PM refcnt for the device,
because the job will never be enqueued or inflight.

Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Link: https://lore.kernel.org/r/20251019145225.3621989-4-adrian.larumbe@collabora.com
Signed-off-by: Steven Price <steven.price@arm.com>

Author: larunbe

drivers/gpu/drm/panfrost/panfrost_job.c

@@ -200,26 +200,27 @@ panfrost_enqueue_job(struct panfrost_device *pfdev, int slot,
 	return 1;
 }
 
-static void panfrost_job_hw_submit(struct panfrost_job *job, int js)
+static int panfrost_job_hw_submit(struct panfrost_job *job, int js)
 {
 	struct panfrost_device *pfdev = job->pfdev;
 	unsigned int subslot;
 	u32 cfg;
 	u64 jc_head = job->jc;
 	int ret;
 
-	panfrost_devfreq_record_busy(&pfdev->pfdevfreq);
-
 	ret = pm_runtime_get_sync(pfdev->base.dev);
 	if (ret < 0)
-		return;
+		goto err_hwsubmit;
 
 	if (WARN_ON(job_read(pfdev, JS_COMMAND_NEXT(js)))) {
-		return;
+		ret = -EINVAL;
+		goto err_hwsubmit;
 	}
 
 	cfg = panfrost_mmu_as_get(pfdev, job->mmu);
 
+	panfrost_devfreq_record_busy(&pfdev->pfdevfreq);
+
 	job_write(pfdev, JS_HEAD_NEXT_LO(js), lower_32_bits(jc_head));
 	job_write(pfdev, JS_HEAD_NEXT_HI(js), upper_32_bits(jc_head));
 
@@ -266,6 +267,12 @@ static void panfrost_job_hw_submit(struct panfrost_job *job, int js)
 			job, js, subslot, jc_head, cfg & 0xf);
 	}
 	spin_unlock(&pfdev->js->job_lock);
+
+	return 0;
+
+err_hwsubmit:
+	pm_runtime_put_autosuspend(pfdev->base.dev);
+	return ret;
 }
 
 static int panfrost_acquire_object_fences(struct drm_gem_object **bos,
@@ -388,6 +395,7 @@ static struct dma_fence *panfrost_job_run(struct drm_sched_job *sched_job)
 	struct panfrost_device *pfdev = job->pfdev;
 	int slot = panfrost_job_get_slot(job);
 	struct dma_fence *fence = NULL;
+	int ret;
 
 	if (job->ctx->destroyed)
 		return ERR_PTR(-ECANCELED);
@@ -409,7 +417,11 @@ static struct dma_fence *panfrost_job_run(struct drm_sched_job *sched_job)
 		dma_fence_put(job->done_fence);
 	job->done_fence = dma_fence_get(fence);
 
-	panfrost_job_hw_submit(job, slot);
+	ret = panfrost_job_hw_submit(job, slot);
+	if (ret) {
+		dma_fence_put(fence);
+		return ERR_PTR(ret);
+	}
 
 	return fence;
 }