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 <[email protected]>
Signed-off-by: Marek Vasut <[email protected]>
---
Cc: "Uwe Kleine-König" <[email protected]>
Cc: Alexandre Torgue <[email protected]>
Cc: Gatien Chevallier <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: Marek Vasut <[email protected]>
Cc: Maxime Coquelin <[email protected]>
Cc: Olivia Mackall <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Yang Yingliang <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
---
V2: Add AB from Gatien
---
drivers/char/hw_random/stm32-rng.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/char/hw_random/stm32-rng.c b/drivers/char/hw_random/stm32-rng.c
index 0e903d6e22e30..6dec4adc49853 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);
--
2.43.0
Place device pointer in struct stm32_rng_private and use it all over the
place to get rid of the horrible type casts throughout the driver.
No functional change.
Acked-by: Gatien Chevallier <[email protected]>
Signed-off-by: Marek Vasut <[email protected]>
---
Cc: "Uwe Kleine-König" <[email protected]>
Cc: Alexandre Torgue <[email protected]>
Cc: Gatien Chevallier <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: Marek Vasut <[email protected]>
Cc: Maxime Coquelin <[email protected]>
Cc: Olivia Mackall <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Yang Yingliang <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
---
V2: Fix up dev_err newlines
Add AB from Gatien
---
drivers/char/hw_random/stm32-rng.c | 30 +++++++++++++-----------------
1 file changed, 13 insertions(+), 17 deletions(-)
diff --git a/drivers/char/hw_random/stm32-rng.c b/drivers/char/hw_random/stm32-rng.c
index 6dec4adc49853..a3d5df176c6e8 100644
--- a/drivers/char/hw_random/stm32-rng.c
+++ b/drivers/char/hw_random/stm32-rng.c
@@ -70,6 +70,7 @@ struct stm32_rng_config {
struct stm32_rng_private {
struct hwrng rng;
+ struct device *dev;
void __iomem *base;
struct clk *clk;
struct reset_control *rst;
@@ -99,7 +100,7 @@ struct stm32_rng_private {
*/
static int stm32_rng_conceal_seed_error_cond_reset(struct stm32_rng_private *priv)
{
- struct device *dev = (struct device *)priv->rng.priv;
+ struct device *dev = priv->dev;
u32 sr = readl_relaxed(priv->base + RNG_SR);
u32 cr = readl_relaxed(priv->base + RNG_CR);
int err;
@@ -171,7 +172,7 @@ static int stm32_rng_conceal_seed_error(struct hwrng *rng)
{
struct stm32_rng_private *priv = container_of(rng, struct stm32_rng_private, rng);
- dev_dbg((struct device *)priv->rng.priv, "Concealing seed error\n");
+ dev_dbg(priv->dev, "Concealing seed error\n");
if (priv->data->has_cond_reset)
return stm32_rng_conceal_seed_error_cond_reset(priv);
@@ -187,7 +188,7 @@ static int stm32_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
int retval = 0, err = 0;
u32 sr;
- retval = pm_runtime_resume_and_get((struct device *)priv->rng.priv);
+ retval = pm_runtime_resume_and_get(priv->dev);
if (retval)
return retval;
@@ -206,8 +207,7 @@ static int stm32_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
sr, sr,
10, 50000);
if (err) {
- dev_err((struct device *)priv->rng.priv,
- "%s: timeout %x!\n", __func__, sr);
+ dev_err(priv->dev, "%s: timeout %x!\n", __func__, sr);
break;
}
} else if (!sr) {
@@ -220,8 +220,7 @@ static int stm32_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
err = stm32_rng_conceal_seed_error(rng);
i++;
if (err && i > RNG_NB_RECOVER_TRIES) {
- dev_err((struct device *)priv->rng.priv,
- "Couldn't recover from seed error\n");
+ dev_err(priv->dev, "Couldn't recover from seed error\n");
retval = -ENOTRECOVERABLE;
goto exit_rpm;
}
@@ -239,8 +238,7 @@ static int stm32_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
err = stm32_rng_conceal_seed_error(rng);
i++;
if (err && i > RNG_NB_RECOVER_TRIES) {
- dev_err((struct device *)priv->rng.priv,
- "Couldn't recover from seed error");
+ dev_err(priv->dev, "Couldn't recover from seed error");
retval = -ENOTRECOVERABLE;
goto exit_rpm;
}
@@ -255,8 +253,8 @@ static int stm32_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
}
exit_rpm:
- pm_runtime_mark_last_busy((struct device *) priv->rng.priv);
- pm_runtime_put_sync_autosuspend((struct device *) priv->rng.priv);
+ pm_runtime_mark_last_busy(priv->dev);
+ pm_runtime_put_sync_autosuspend(priv->dev);
return retval || !wait ? retval : -EIO;
}
@@ -331,8 +329,7 @@ static int stm32_rng_init(struct hwrng *rng)
10, 50000);
if (err) {
clk_disable_unprepare(priv->clk);
- dev_err((struct device *)priv->rng.priv,
- "%s: timeout %x!\n", __func__, reg);
+ dev_err(priv->dev, "%s: timeout %x!\n", __func__, reg);
return -EINVAL;
}
} else {
@@ -360,8 +357,7 @@ static int stm32_rng_init(struct hwrng *rng)
10, 100000);
if (err || (reg & ~RNG_SR_DRDY)) {
clk_disable_unprepare(priv->clk);
- dev_err((struct device *)priv->rng.priv,
- "%s: timeout:%x SR: %x!\n", __func__, err, reg);
+ dev_err(priv->dev, "%s: timeout:%x SR: %x!\n", __func__, err, reg);
return -EINVAL;
}
@@ -467,8 +463,7 @@ static int __maybe_unused stm32_rng_resume(struct device *dev)
if (err) {
clk_disable_unprepare(priv->clk);
- dev_err((struct device *)priv->rng.priv,
- "%s: timeout:%x CR: %x!\n", __func__, err, reg);
+ dev_err(priv->dev, "%s: timeout:%x CR: %x!\n", __func__, err, reg);
return -EINVAL;
}
} else {
@@ -543,6 +538,7 @@ static int stm32_rng_probe(struct platform_device *ofdev)
priv->ced = of_property_read_bool(np, "clock-error-detect");
priv->lock_conf = of_property_read_bool(np, "st,rng-lock-conf");
+ priv->dev = dev;
priv->data = of_device_get_match_data(dev);
if (!priv->data)
--
2.43.0
On 5/31/24 7:06 AM, Herbert Xu wrote:
> On Thu, May 16, 2024 at 09:37:41PM +0200, Marek Vasut wrote:
>> Place device pointer in struct stm32_rng_private and use it all over the
>> place to get rid of the horrible type casts throughout the driver.
>>
>> No functional change.
>>
>> Acked-by: Gatien Chevallier <[email protected]>
>> Signed-off-by: Marek Vasut <[email protected]>
>
> I think you should remove the assignment of rng.priv too as nothing
> should use it anymore after your patch.
Fixed in V3, thanks.