[PATCH] optee: fix the dead loop problem when there is signal pending

[Zeng Tao]

when the current process is doing a rpc call from optee, and if there
is a signal pending on the process, it will enter dead loop if the
tee-supplicant is working correctly, fix the problem by breaking out
the loop when the rpc job is finished.

Signed-off-by: Zeng Tao <prime.zeng@xxxxxxxxxxxxx>
---
 drivers/tee/optee/supp.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/tee/optee/supp.c b/drivers/tee/optee/supp.c
index b4ea067..170dedb 100644
--- a/drivers/tee/optee/supp.c
+++ b/drivers/tee/optee/supp.c
@@ -107,6 +107,13 @@ u32 optee_supp_thrd_req(struct tee_context *ctx, u32 func, size_t num_params,
 		mutex_unlock(&supp->ctx_mutex);
 		if (interruptable)
 			break;
+
+		/*
+		 * if there is signal pending, and the supplicant has finished
+		 * the rpc job, we need to break out the loop
+		 */
+		if (try_wait_for_completion(&supp->data_from_supp))
+			break;
 	}
 
 	ret = supp->ret;
-- 
2.7.4