[PATCH v6 1/2] accel/rocket: Fix error path handling in rocket_job_run()

[ZhaoJinming <zhaojinming@uniontech.com>]

In rocket_job_run(), after taking an extra fence reference for
job->done_fence via dma_fence_get(), the error paths have three bugs:

- The dma_fence reference held by job->done_fence is never released,
  causing a reference leak.
- pm_runtime_get_sync() increments the usage counter even on failure,
  but the error path does not decrement it, leaking the runtime PM
  reference and preventing the NPU from suspending.
- A valid but unsignaled fence is returned to the DRM scheduler,
  which triggers WARN("Fence ... released with pending signals!")
  when the scheduler drops its reference.

Fix by replacing pm_runtime_get_sync() with pm_runtime_resume_and_get()
which auto-balances the usage counter on failure, releasing both fence
references on error, and returning ERR_PTR(ret) instead of the
unsignaled fence.

Cc: stable@vger.kernel.org
Fixes: 0810d5ad88a1 ("accel/rocket: Add job submission IOCTL")
Signed-off-by: ZhaoJinming <zhaojinming@uniontech.com>
---
 drivers/accel/rocket/rocket_job.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/accel/rocket/rocket_job.c b/drivers/accel/rocket/rocket_job.c
index ac51bff39833..e8a073e22ac2 100644
--- a/drivers/accel/rocket/rocket_job.c
+++ b/drivers/accel/rocket/rocket_job.c
@@ -310,13 +310,22 @@ static struct dma_fence *rocket_job_run(struct drm_sched_job *sched_job)
 		dma_fence_put(job->done_fence);
 	job->done_fence = dma_fence_get(fence);
 
-	ret = pm_runtime_get_sync(core->dev);
-	if (ret < 0)
-		return fence;
+	ret = pm_runtime_resume_and_get(core->dev);
+	if (ret < 0) {
+		dma_fence_put(job->done_fence);
+		job->done_fence = NULL;
+		dma_fence_put(fence);
+		return ERR_PTR(ret);
+	}
 
 	ret = iommu_attach_group(job->domain->domain, core->iommu_group);
-	if (ret < 0)
-		return fence;
+	if (ret < 0) {
+		pm_runtime_put(core->dev);
+		dma_fence_put(job->done_fence);
+		job->done_fence = NULL;
+		dma_fence_put(fence);
+		return ERR_PTR(ret);
+	}
 
 	scoped_guard(mutex, &core->job_lock) {
 		core->in_flight_job = job;
-- 
2.20.1