diff options
| author | Marek Vasut <marex@denx.de> | 2024-05-31 10:53:22 +0200 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2024-06-07 19:46:39 +0800 |
| commit | f134d5dce9c1f70fb522712b306644deb1e6eccd (patch) | |
| tree | 6ea25392c686ee879d1c5d6e68851d303fb93ab8 /drivers/char/hw_random | |
| parent | 3aeb1da092e875255c24c6a26be097448d70a756 (diff) | |
hwrng: stm32 - use pm_runtime_resume_and_get()
include/linux/pm_runtime.h pm_runtime_get_sync() description suggests to
... consider using pm_runtime_resume_and_get() instead of it, especially
if its return value is checked by the caller, as this is likely to result
in cleaner code.
This is indeed better, switch to pm_runtime_resume_and_get() which
correctly suspends the device again in case of failure. Also add error
checking into the RNG driver in case pm_runtime_resume_and_get() does
fail, which is currently not done, and it does detect sporadic -EACCES
error return after resume, which would otherwise lead to a hang due to
register access on un-resumed hardware. Now the read simply errors out
and the system does not hang.
Acked-by: Gatien Chevallier <gatien.chevallier@foss.st.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/char/hw_random')
| -rw-r--r-- | drivers/char/hw_random/stm32-rng.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/char/hw_random/stm32-rng.c b/drivers/char/hw_random/stm32-rng.c index 0e903d6e22e3..6dec4adc4985 100644 --- a/drivers/char/hw_random/stm32-rng.c +++ b/drivers/char/hw_random/stm32-rng.c @@ -187,7 +187,9 @@ static int stm32_rng_read(struct hwrng *rng, void *data, size_t max, bool wait) int retval = 0, err = 0; u32 sr; - pm_runtime_get_sync((struct device *) priv->rng.priv); + retval = pm_runtime_resume_and_get((struct device *)priv->rng.priv); + if (retval) + return retval; if (readl_relaxed(priv->base + RNG_SR) & RNG_SR_SEIS) stm32_rng_conceal_seed_error(rng); |