[PATCH] hwrng: exynos - Fix unbalanced PM runtime get/puts

From: Daniel Thompson
Date: Fri Oct 16 2015 - 12:02:20 EST


Currently this driver calls pm_runtime_get_sync() rampantly
but never puts anything back. This makes it impossible for the
device to autosuspend properly; it will remain fully active
after the first use.

Fix in the obvious way.

Signed-off-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
Cc: Kukjin Kim <kgene@xxxxxxxxxx>
Cc: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>
---

Notes:
Compile tested only (CONFIG_PM=y, CONFIG_HW_RANDOM_EXYNOS=m); I spotted
this whilst reviewing the code and don't have an exynos platform to
test on.

drivers/char/hw_random/exynos-rng.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/char/hw_random/exynos-rng.c b/drivers/char/hw_random/exynos-rng.c
index dc4701fd814f..73318e2a34dd 100644
--- a/drivers/char/hw_random/exynos-rng.c
+++ b/drivers/char/hw_random/exynos-rng.c
@@ -95,7 +95,7 @@ static int exynos_read(struct hwrng *rng, void *buf,
*data = exynos_rng_readl(exynos_rng, EXYNOS_PRNG_OUT1_OFFSET);

pm_runtime_mark_last_busy(exynos_rng->dev);
- pm_runtime_autosuspend(exynos_rng->dev);
+ pm_runtime_put_sync_autosuspend(exynos_rng->dev);

return 4;
}
--
2.4.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/