diff mbox

[V3,9/9] PM / OPP: Don't assume platform doesn't have regulators

Message ID f1fa8223ab9b9a1183626ec42608ec966a4bc425.1477463128.git.viresh.kumar@linaro.org
State Superseded
Headers show

Commit Message

Viresh Kumar Oct. 26, 2016, 6:33 a.m. UTC
If the regulators aren't set explicitly by the platform, the OPP core
assumes that the platform doesn't have any regulator and uses the
clk-only callback.

If the platform failed to register a regulator with the core, then this
can turn out to be a dangerous assumption as the OPP core will try to
change clk without changing regulators.

Handle that properly by making sure that the DT didn't had any entries
for supply voltages as well.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

---
 drivers/base/power/opp/core.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

-- 
2.7.1.410.g6faf27b

--
To unsubscribe from this list: send the line "unsubscribe linux-pm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Comments

Stephen Boyd Nov. 10, 2016, 1:17 a.m. UTC | #1
On 10/26, Viresh Kumar wrote:
> If the regulators aren't set explicitly by the platform, the OPP core

> assumes that the platform doesn't have any regulator and uses the

> clk-only callback.

> 

> If the platform failed to register a regulator with the core, then this

> can turn out to be a dangerous assumption as the OPP core will try to

> change clk without changing regulators.

> 

> Handle that properly by making sure that the DT didn't had any entries


s/had/have/

> for supply voltages as well.

> 

> diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c

> index 3298fac01bb0..34cd48dfe89e 100644

> --- a/drivers/base/power/opp/core.c

> +++ b/drivers/base/power/opp/core.c

> @@ -734,7 +734,17 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)

>  

>  	/* Only frequency scaling */

>  	if (!regulators) {

> -		rcu_read_unlock();

> +		/*

> +		 * DT contained supply ratings? Consider platform failed to set

> +		 * regulators.

> +		 */

> +		if (unlikely(opp->supplies[0].u_volt)) {

> +			rcu_read_unlock();

> +			dev_err(dev, "%s: Regulator not registered with OPP core\n",

> +				__func__);

> +			return -EINVAL;

> +		}

> +


Don't we need an rcu_read_unlock() here as well?

>  		return _generic_set_opp_clk_only(dev, clk, old_freq, freq);

>  	}

>  


-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
--
To unsubscribe from this list: send the line "unsubscribe linux-pm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
index 3298fac01bb0..34cd48dfe89e 100644
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c
@@ -734,7 +734,17 @@  int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
 
 	/* Only frequency scaling */
 	if (!regulators) {
-		rcu_read_unlock();
+		/*
+		 * DT contained supply ratings? Consider platform failed to set
+		 * regulators.
+		 */
+		if (unlikely(opp->supplies[0].u_volt)) {
+			rcu_read_unlock();
+			dev_err(dev, "%s: Regulator not registered with OPP core\n",
+				__func__);
+			return -EINVAL;
+		}
+
 		return _generic_set_opp_clk_only(dev, clk, old_freq, freq);
 	}