[PATCH 2/3] hwrng: stm32 - put IP into RPM suspend on failure

[Marek Vasut]

In case of an irrecoverable failure, put the IP into RPM suspend
to avoid RPM imbalance. I did not trigger this case, but it seems
it should be done based on reading the code.

Fixes: b17bc6eb7c2b ("hwrng: stm32 - rework error handling in stm32_rng_read()")
Signed-off-by: Marek Vasut <marex at denx.de>
---
Cc: "Uwe Kleine-König" <u.kleine-koenig at pengutronix.de>
Cc: Alexandre Torgue <alexandre.torgue at foss.st.com>
Cc: Gatien Chevallier <gatien.chevallier at foss.st.com>
Cc: Herbert Xu <herbert at gondor.apana.org.au>
Cc: Maxime Coquelin <mcoquelin.stm32 at gmail.com>
Cc: Olivia Mackall <olivia at selenic.com>
Cc: Rob Herring <robh at kernel.org>
Cc: Yang Yingliang <yangyingliang at huawei.com>
Cc: kernel at dh-electronics.com
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-crypto at vger.kernel.org
Cc: linux-stm32 at st-md-mailman.stormreply.com
---
 drivers/char/hw_random/stm32-rng.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/char/hw_random/stm32-rng.c b/drivers/char/hw_random/stm32-rng.c
index 1cc61ef8ee54c..b6182f86d8a4b 100644
--- a/drivers/char/hw_random/stm32-rng.c
+++ b/drivers/char/hw_random/stm32-rng.c
@@ -220,7 +220,8 @@ static int stm32_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
 				if (err && i > RNG_NB_RECOVER_TRIES) {
 					dev_err((struct device *)priv->rng.priv,
 						"Couldn't recover from seed error\n");
-					return -ENOTRECOVERABLE;
+					retval = -ENOTRECOVERABLE;
+					goto exit_rpm;
 				}
 
 				continue;
@@ -238,7 +239,8 @@ static int stm32_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
 			if (err && i > RNG_NB_RECOVER_TRIES) {
 				dev_err((struct device *)priv->rng.priv,
 					"Couldn't recover from seed error");
-				return -ENOTRECOVERABLE;
+				retval = -ENOTRECOVERABLE;
+				goto exit_rpm;
 			}
 
 			continue;
@@ -250,6 +252,7 @@ static int stm32_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
 		max -= sizeof(u32);
 	}
 
+exit_rpm:
 	pm_runtime_mark_last_busy((struct device *) priv->rng.priv);
 	pm_runtime_put_sync_autosuspend((struct device *) priv->rng.priv);
 
-- 
2.43.0