* [PATCH 1/2] hwrng: stm32 - use pm_runtime_resume_and_get() @ 2024-05-16 1:20 Marek Vasut 2024-05-16 1:20 ` [PATCH 2/2] hwrng: stm32 - cache device pointer in struct stm32_rng_private Marek Vasut 2024-05-16 8:12 ` [PATCH 1/2] hwrng: stm32 - use pm_runtime_resume_and_get() Gatien CHEVALLIER 0 siblings, 2 replies; 6+ messages in thread From: Marek Vasut @ 2024-05-16 1:20 UTC (permalink / raw) To: linux-crypto Cc: Marek Vasut, Uwe Kleine-König, Alexandre Torgue, Gatien Chevallier, Herbert Xu, Maxime Coquelin, Olivia Mackall, Rob Herring, Yang Yingliang, kernel, linux-arm-kernel, linux-stm32 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. Signed-off-by: Marek Vasut <marex@denx.de> --- Cc: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: Gatien Chevallier <gatien.chevallier@foss.st.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Marek Vasut <marex@denx.de> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Olivia Mackall <olivia@selenic.com> Cc: Rob Herring <robh@kernel.org> Cc: Yang Yingliang <yangyingliang@huawei.com> Cc: kernel@dh-electronics.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-crypto@vger.kernel.org Cc: linux-stm32@st-md-mailman.stormreply.com --- 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 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 2/2] hwrng: stm32 - cache device pointer in struct stm32_rng_private 2024-05-16 1:20 [PATCH 1/2] hwrng: stm32 - use pm_runtime_resume_and_get() Marek Vasut @ 2024-05-16 1:20 ` Marek Vasut 2024-05-16 9:37 ` Gatien CHEVALLIER 2024-05-16 8:12 ` [PATCH 1/2] hwrng: stm32 - use pm_runtime_resume_and_get() Gatien CHEVALLIER 1 sibling, 1 reply; 6+ messages in thread From: Marek Vasut @ 2024-05-16 1:20 UTC (permalink / raw) To: linux-crypto Cc: Marek Vasut, Uwe Kleine-König, Alexandre Torgue, Gatien Chevallier, Herbert Xu, Maxime Coquelin, Olivia Mackall, Rob Herring, Yang Yingliang, kernel, linux-arm-kernel, linux-stm32 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. Signed-off-by: Marek Vasut <marex@denx.de> --- Cc: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: Gatien Chevallier <gatien.chevallier@foss.st.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Marek Vasut <marex@denx.de> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Olivia Mackall <olivia@selenic.com> Cc: Rob Herring <robh@kernel.org> Cc: Yang Yingliang <yangyingliang@huawei.com> Cc: kernel@dh-electronics.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-crypto@vger.kernel.org Cc: linux-stm32@st-md-mailman.stormreply.com --- drivers/char/hw_random/stm32-rng.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-) diff --git a/drivers/char/hw_random/stm32-rng.c b/drivers/char/hw_random/stm32-rng.c index 6dec4adc49853..00012e6e4ccc8 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; @@ -206,7 +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, + dev_err(priv->dev, "%s: timeout %x!\n", __func__, sr); break; } @@ -220,7 +221,7 @@ 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, + dev_err(priv->dev, "Couldn't recover from seed error\n"); retval = -ENOTRECOVERABLE; goto exit_rpm; @@ -239,7 +240,7 @@ 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, + dev_err(priv->dev, "Couldn't recover from seed error"); retval = -ENOTRECOVERABLE; goto exit_rpm; @@ -255,8 +256,8 @@ 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 +332,7 @@ 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 { @@ -360,7 +360,7 @@ 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, + dev_err(priv->dev, "%s: timeout:%x SR: %x!\n", __func__, err, reg); return -EINVAL; } @@ -467,7 +467,7 @@ static int __maybe_unused stm32_rng_resume(struct device *dev) if (err) { clk_disable_unprepare(priv->clk); - dev_err((struct device *)priv->rng.priv, + dev_err(priv->dev, "%s: timeout:%x CR: %x!\n", __func__, err, reg); return -EINVAL; } @@ -543,6 +543,7 @@ 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 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] hwrng: stm32 - cache device pointer in struct stm32_rng_private 2024-05-16 1:20 ` [PATCH 2/2] hwrng: stm32 - cache device pointer in struct stm32_rng_private Marek Vasut @ 2024-05-16 9:37 ` Gatien CHEVALLIER 2024-05-16 10:52 ` Marek Vasut 0 siblings, 1 reply; 6+ messages in thread From: Gatien CHEVALLIER @ 2024-05-16 9:37 UTC (permalink / raw) To: Marek Vasut, linux-crypto Cc: Uwe Kleine-König, Alexandre Torgue, Herbert Xu, Maxime Coquelin, Olivia Mackall, Rob Herring, Yang Yingliang, kernel, linux-arm-kernel, linux-stm32 On 5/16/24 03:20, 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. > > Signed-off-by: Marek Vasut <marex@denx.de> > --- > Cc: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de> > Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> > Cc: Gatien Chevallier <gatien.chevallier@foss.st.com> > Cc: Herbert Xu <herbert@gondor.apana.org.au> > Cc: Marek Vasut <marex@denx.de> > Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> > Cc: Olivia Mackall <olivia@selenic.com> > Cc: Rob Herring <robh@kernel.org> > Cc: Yang Yingliang <yangyingliang@huawei.com> > Cc: kernel@dh-electronics.com > Cc: linux-arm-kernel@lists.infradead.org > Cc: linux-crypto@vger.kernel.org > Cc: linux-stm32@st-md-mailman.stormreply.com > --- > drivers/char/hw_random/stm32-rng.c | 25 +++++++++++++------------ > 1 file changed, 13 insertions(+), 12 deletions(-) > > diff --git a/drivers/char/hw_random/stm32-rng.c b/drivers/char/hw_random/stm32-rng.c > index 6dec4adc49853..00012e6e4ccc8 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; > > @@ -206,7 +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, > + dev_err(priv->dev, > "%s: timeout %x!\n", __func__, sr); Nit: Fits in one line > break; > } > @@ -220,7 +221,7 @@ 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, > + dev_err(priv->dev, > "Couldn't recover from seed error\n"); Nit: Fits in one line > retval = -ENOTRECOVERABLE; > goto exit_rpm; > @@ -239,7 +240,7 @@ 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, > + dev_err(priv->dev, > "Couldn't recover from seed error"); Nit: Fits in one line > retval = -ENOTRECOVERABLE; > goto exit_rpm; > @@ -255,8 +256,8 @@ 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 +332,7 @@ 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 { > @@ -360,7 +360,7 @@ 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, > + dev_err(priv->dev, > "%s: timeout:%x SR: %x!\n", __func__, err, reg); Nit: Fits in one line > return -EINVAL; > } > @@ -467,7 +467,7 @@ static int __maybe_unused stm32_rng_resume(struct device *dev) > > if (err) { > clk_disable_unprepare(priv->clk); > - dev_err((struct device *)priv->rng.priv, > + dev_err(priv->dev, > "%s: timeout:%x CR: %x!\n", __func__, err, reg); > return -EINVAL; > } > @@ -543,6 +543,7 @@ 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) With nits applied, Acked-by: Gatien Chevallier <gatien.chevallier@foss.st.com> _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] hwrng: stm32 - cache device pointer in struct stm32_rng_private 2024-05-16 9:37 ` Gatien CHEVALLIER @ 2024-05-16 10:52 ` Marek Vasut 2024-05-16 11:47 ` Gatien CHEVALLIER 0 siblings, 1 reply; 6+ messages in thread From: Marek Vasut @ 2024-05-16 10:52 UTC (permalink / raw) To: Gatien CHEVALLIER, linux-crypto Cc: Uwe Kleine-König, Alexandre Torgue, Herbert Xu, Maxime Coquelin, Olivia Mackall, Rob Herring, Yang Yingliang, kernel, linux-arm-kernel, linux-stm32 On 5/16/24 11:37 AM, Gatien CHEVALLIER wrote: Hi, >> diff --git a/drivers/char/hw_random/stm32-rng.c >> b/drivers/char/hw_random/stm32-rng.c >> index 6dec4adc49853..00012e6e4ccc8 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; >> @@ -206,7 +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, >> + dev_err(priv->dev, >> "%s: timeout %x!\n", __func__, sr); > > Nit: Fits in one line The limit is now 100 instead of 80 chars, right ? btw I found one more and fixed it. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/2] hwrng: stm32 - cache device pointer in struct stm32_rng_private 2024-05-16 10:52 ` Marek Vasut @ 2024-05-16 11:47 ` Gatien CHEVALLIER 0 siblings, 0 replies; 6+ messages in thread From: Gatien CHEVALLIER @ 2024-05-16 11:47 UTC (permalink / raw) To: Marek Vasut, linux-crypto Cc: Uwe Kleine-König, Alexandre Torgue, Herbert Xu, Maxime Coquelin, Olivia Mackall, Rob Herring, Yang Yingliang, kernel, linux-arm-kernel, linux-stm32 On 5/16/24 12:52, Marek Vasut wrote: > On 5/16/24 11:37 AM, Gatien CHEVALLIER wrote: > > Hi, > >>> diff --git a/drivers/char/hw_random/stm32-rng.c >>> b/drivers/char/hw_random/stm32-rng.c >>> index 6dec4adc49853..00012e6e4ccc8 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; >>> @@ -206,7 +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, >>> + dev_err(priv->dev, >>> "%s: timeout %x!\n", __func__, sr); >> >> Nit: Fits in one line > > The limit is now 100 instead of 80 chars, right ? > > btw I found one more and fixed it. Yes it is, thanks _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/2] hwrng: stm32 - use pm_runtime_resume_and_get() 2024-05-16 1:20 [PATCH 1/2] hwrng: stm32 - use pm_runtime_resume_and_get() Marek Vasut 2024-05-16 1:20 ` [PATCH 2/2] hwrng: stm32 - cache device pointer in struct stm32_rng_private Marek Vasut @ 2024-05-16 8:12 ` Gatien CHEVALLIER 1 sibling, 0 replies; 6+ messages in thread From: Gatien CHEVALLIER @ 2024-05-16 8:12 UTC (permalink / raw) To: Marek Vasut, linux-crypto Cc: Uwe Kleine-König, Alexandre Torgue, Herbert Xu, Maxime Coquelin, Olivia Mackall, Rob Herring, Yang Yingliang, kernel, linux-arm-kernel, linux-stm32 On 5/16/24 03:20, Marek Vasut wrote: > 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. > > Signed-off-by: Marek Vasut <marex@denx.de> > --- > Cc: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de> > Cc: Alexandre Torgue <alexandre.torgue@foss.st.com> > Cc: Gatien Chevallier <gatien.chevallier@foss.st.com> > Cc: Herbert Xu <herbert@gondor.apana.org.au> > Cc: Marek Vasut <marex@denx.de> > Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> > Cc: Olivia Mackall <olivia@selenic.com> > Cc: Rob Herring <robh@kernel.org> > Cc: Yang Yingliang <yangyingliang@huawei.com> > Cc: kernel@dh-electronics.com > Cc: linux-arm-kernel@lists.infradead.org > Cc: linux-crypto@vger.kernel.org > Cc: linux-stm32@st-md-mailman.stormreply.com > --- > 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); Hi Marek, I'll check in other stm32 drivers as well. Acked-by: Gatien Chevallier <gatien.chevallier@foss.st.com> Thanks, Gatien _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2024-05-16 11:48 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2024-05-16 1:20 [PATCH 1/2] hwrng: stm32 - use pm_runtime_resume_and_get() Marek Vasut 2024-05-16 1:20 ` [PATCH 2/2] hwrng: stm32 - cache device pointer in struct stm32_rng_private Marek Vasut 2024-05-16 9:37 ` Gatien CHEVALLIER 2024-05-16 10:52 ` Marek Vasut 2024-05-16 11:47 ` Gatien CHEVALLIER 2024-05-16 8:12 ` [PATCH 1/2] hwrng: stm32 - use pm_runtime_resume_and_get() Gatien CHEVALLIER
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