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From:   Christoph Gellner <cgellner@de.adit-jv.com>
To:     <op-tee@lists.trustedfirmware.org>, <linux-kernel@vger.kernel.org>
CC:     <jens.wiklander@linaro.org>,
        Christoph Gellner <cgellner@de.adit-jv.com>
Subject: [RFC PATCH 3/3] tee: optee: Allow to freeze while waiting in OPTEE_RPC_WAIT_QUEUE_SLEEP
Date:   Wed, 26 May 2021 09:09:11 +0200
Message-ID: <20210526070911.31681-4-cgellner@de.adit-jv.com>
In-Reply-To: <20210526070911.31681-1-cgellner@de.adit-jv.com>
References: <20210526070911.31681-1-cgellner@de.adit-jv.com>
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When the system is going to hibernate or suspend and the task calling
the corresponding OPTEE_RPC_WAIT_QUEUE_WAKEUP gets frozen waiting
for completion in OPTEE_RPC_WAIT_QUEUE_SLEEP might get stuck.

Change wait to interruptible and add try_to_freeze in order to
allow that the waiting task is frozen as well.

Signed-off-by: Christoph Gellner <cgellner@de.adit-jv.com>
---
 drivers/tee/optee/rpc.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/tee/optee/rpc.c b/drivers/tee/optee/rpc.c
index 1849180b0278..0851b19be529 100644
--- a/drivers/tee/optee/rpc.c
+++ b/drivers/tee/optee/rpc.c
@@ -10,6 +10,7 @@
 #include <linux/i2c.h>
 #include <linux/slab.h>
 #include <linux/tee_drv.h>
+#include <linux/freezer.h>
 #include "optee_private.h"
 #include "optee_smc.h"
 #include "optee_rpc_cmd.h"
@@ -169,7 +170,13 @@ static void wq_sleep(struct optee_wait_queue *wq, u32 key)
 	struct wq_entry *w = wq_entry_get(wq, key);
 
 	if (w) {
-		wait_for_completion(&w->c);
+		/*
+		 * wait_for_completion but allow hibernation/suspend
+		 * to freeze the waiting task
+		 */
+		while (wait_for_completion_interruptible(&w->c))
+			try_to_freeze();
+
 		mutex_lock(&wq->mu);
 		list_del(&w->link);
 		mutex_unlock(&wq->mu);
-- 
2.32.0.rc0