The starfive_trng_read() function acquires a runtime PM reference
via pm_runtime_get_sync() but fails to release it on two error
paths. If starfive_trng_wait_idle() or starfive_trng_cmd() returns
an error, the function exits without calling
pm_runtime_put_sync_autosuspend(), leaving the runtime PM usage
counter permanently elevated and preventing the device from entering
runtime suspend.
Refactor the function to use a unified error path that calls
pm_runtime_put_sync_autosuspend() before returning.
Cc: stable@vger.kernel.org
Fixes: c388f458bc34 ("hwrng: starfive - Add TRNG driver for StarFive SoC")
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
---
drivers/char/hw_random/jh7110-trng.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/drivers/char/hw_random/jh7110-trng.c b/drivers/char/hw_random/jh7110-trng.c
index 9776f4daa044..4712c3c530e4 100644
--- a/drivers/char/hw_random/jh7110-trng.c
+++ b/drivers/char/hw_random/jh7110-trng.c
@@ -256,19 +256,22 @@ static int starfive_trng_read(struct hwrng *rng, void *buf, size_t max, bool wai
if (wait) {
ret = starfive_trng_wait_idle(trng);
- if (ret)
- return -ETIMEDOUT;
+ if (ret) {
+ ret = -ETIMEDOUT;
+ goto out_put;
+ }
}
ret = starfive_trng_cmd(trng, STARFIVE_CTRL_GENE_RANDNUM, wait);
if (ret)
- return ret;
+ goto out_put;
memcpy_fromio(buf, trng->base + STARFIVE_RAND0, max);
+ ret = max;
+out_put:
pm_runtime_put_sync_autosuspend(trng->dev);
-
- return max;
+ return ret;
}
static int starfive_trng_probe(struct platform_device *pdev)
--
2.34.1