[PATCH] accel/amdxdna: Fix deadlock between context destroy and job timeout

[Lizhi Hou]

Hardware context destroy function holds dev_lock while waiting for all jobs
to complete. The timeout job also needs to acquire dev_lock, this leads to
a deadlock.

Fix the issue by temporarily releasing dev_lock before waiting for all
jobs to finish, and reacquiring it afterward.

Fixes: 4fd6ca90fc7f ("accel/amdxdna: Refactor hardware context destroy routine")
Signed-off-by: Lizhi Hou <lizhi.hou@xxxxxxx>
---
 drivers/accel/amdxdna/aie2_ctx.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/accel/amdxdna/aie2_ctx.c b/drivers/accel/amdxdna/aie2_ctx.c
index bdc90fe8a47e..42d876a427c5 100644
--- a/drivers/accel/amdxdna/aie2_ctx.c
+++ b/drivers/accel/amdxdna/aie2_ctx.c
@@ -690,17 +690,19 @@ void aie2_hwctx_fini(struct amdxdna_hwctx *hwctx)
 	xdna = hwctx->client->xdna;
 
 	XDNA_DBG(xdna, "%s sequence number %lld", hwctx->name, hwctx->priv->seq);
-	drm_sched_entity_destroy(&hwctx->priv->entity);
-
 	aie2_hwctx_wait_for_idle(hwctx);
 
 	/* Request fw to destroy hwctx and cancel the rest pending requests */
 	aie2_release_resource(hwctx);
 
+	mutex_unlock(&xdna->dev_lock);
+	drm_sched_entity_destroy(&hwctx->priv->entity);
+
 	/* Wait for all submitted jobs to be completed or canceled */
 	wait_event(hwctx->priv->job_free_wq,
 		   atomic64_read(&hwctx->job_submit_cnt) ==
 		   atomic64_read(&hwctx->job_free_cnt));
+	mutex_lock(&xdna->dev_lock);
 
 	drm_sched_fini(&hwctx->priv->sched);
 	aie2_ctx_syncobj_destroy(hwctx);
-- 
2.34.1