diff mbox

[01/10] PM / OPP: Fix memory leak while adding duplicate OPPs

Message ID d4addab7750d63731d8e8562e2600fa8c987f53a.1481015522.git.viresh.kumar@linaro.org
State Superseded
Headers show

Commit Message

Viresh Kumar Dec. 6, 2016, 9:15 a.m. UTC
There are two types of duplicate OPPs that get different behavior from
the core:
A). An earlier OPP is marked 'available' and has same freq/voltages as
    the new one.
B). An earlier OPP with same frequency, but is marked 'unavailable' OR
    doesn't have same voltages as the new one.

The OPP core returns 0 for the first one, but -EEXIST for the second.

While the OPP core returns 0 for the first case, its callers don't free
the newly allocated OPP structure which isn't used anymore. Fix that by
returning -EBUSY instead of 0, but make the callers return 0 eventually.

As this isn't a critical fix, its not getting marked for stable kernel.

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

---
 drivers/base/power/opp/core.c | 14 ++++++++++++--
 drivers/base/power/opp/of.c   |  6 +++++-
 2 files changed, 17 insertions(+), 3 deletions(-)

-- 
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 Dec. 7, 2016, 1:09 a.m. UTC | #1
On 12/06, Viresh Kumar wrote:
> There are two types of duplicate OPPs that get different behavior from

> the core:

> A). An earlier OPP is marked 'available' and has same freq/voltages as

>     the new one.

> B). An earlier OPP with same frequency, but is marked 'unavailable' OR

>     doesn't have same voltages as the new one.

> 

> The OPP core returns 0 for the first one, but -EEXIST for the second.

> 

> While the OPP core returns 0 for the first case, its callers don't free

> the newly allocated OPP structure which isn't used anymore. Fix that by

> returning -EBUSY instead of 0, but make the callers return 0 eventually.

> 

> As this isn't a critical fix, its not getting marked for stable kernel.

> 

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


Makes sense.

> ---

>  drivers/base/power/opp/core.c | 14 ++++++++++++--

>  drivers/base/power/opp/of.c   |  6 +++++-

>  2 files changed, 17 insertions(+), 3 deletions(-)

> 

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

> index a0e6294baf1d..cc69f903fd34 100644

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

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

> @@ -1080,6 +1080,12 @@ static bool _opp_supported_by_regulators(struct dev_pm_opp *opp,

>  	return true;

>  }

>  

> +/*

> + * Returns:

> + * 0: On success. And appropriate error message for Duplicate OPPs.


lowercase duplicate please

> + * -EBUSY: For OPP with same freq/volt and is available.

> + * -EEXIST: For OPP with same freq but different volt or is unavailable.

> + */

>  int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,

>  	     struct opp_table *opp_table)

>  {

> @@ -1112,7 +1118,7 @@ int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,

>  

>  		/* Should we compare voltages for all regulators here ? */

>  		return opp->available &&

> -		       new_opp->supplies[0].u_volt == opp->supplies[0].u_volt ? 0 : -EEXIST;

> +		       new_opp->supplies[0].u_volt == opp->supplies[0].u_volt ? -EBUSY : -EEXIST;

>  	}

>  

>  	new_opp->opp_table = opp_table;

> @@ -1186,8 +1192,12 @@ int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt,

>  	new_opp->dynamic = dynamic;

>  

>  	ret = _opp_add(dev, new_opp, opp_table);

> -	if (ret)

> +	if (ret) {

> +		/* Don't return error for duplicate OPPs */


Yes, but why?

> +		if (ret == -EBUSY)

> +			ret = 0;

>  		goto free_opp;

> +	}

>  

>  	mutex_unlock(&opp_table_lock);

>  


-- 
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
Viresh Kumar Dec. 7, 2016, 3:23 a.m. UTC | #2
On 06-12-16, 17:09, Stephen Boyd wrote:
> > @@ -1186,8 +1192,12 @@ int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt,

> >  	new_opp->dynamic = dynamic;

> >  

> >  	ret = _opp_add(dev, new_opp, opp_table);

> > -	if (ret)

> > +	if (ret) {

> > +		/* Don't return error for duplicate OPPs */

> 

> Yes, but why?


Will update the comment over _opp_add() to describe that.

-- 
viresh
--
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 a0e6294baf1d..cc69f903fd34 100644
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c
@@ -1080,6 +1080,12 @@  static bool _opp_supported_by_regulators(struct dev_pm_opp *opp,
 	return true;
 }
 
+/*
+ * Returns:
+ * 0: On success. And appropriate error message for Duplicate OPPs.
+ * -EBUSY: For OPP with same freq/volt and is available.
+ * -EEXIST: For OPP with same freq but different volt or is unavailable.
+ */
 int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
 	     struct opp_table *opp_table)
 {
@@ -1112,7 +1118,7 @@  int _opp_add(struct device *dev, struct dev_pm_opp *new_opp,
 
 		/* Should we compare voltages for all regulators here ? */
 		return opp->available &&
-		       new_opp->supplies[0].u_volt == opp->supplies[0].u_volt ? 0 : -EEXIST;
+		       new_opp->supplies[0].u_volt == opp->supplies[0].u_volt ? -EBUSY : -EEXIST;
 	}
 
 	new_opp->opp_table = opp_table;
@@ -1186,8 +1192,12 @@  int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt,
 	new_opp->dynamic = dynamic;
 
 	ret = _opp_add(dev, new_opp, opp_table);
-	if (ret)
+	if (ret) {
+		/* Don't return error for duplicate OPPs */
+		if (ret == -EBUSY)
+			ret = 0;
 		goto free_opp;
+	}
 
 	mutex_unlock(&opp_table_lock);
 
diff --git a/drivers/base/power/opp/of.c b/drivers/base/power/opp/of.c
index 3f7d2591b173..356c75edd656 100644
--- a/drivers/base/power/opp/of.c
+++ b/drivers/base/power/opp/of.c
@@ -327,8 +327,12 @@  static int _opp_add_static_v2(struct device *dev, struct device_node *np)
 		goto free_opp;
 
 	ret = _opp_add(dev, new_opp, opp_table);
-	if (ret)
+	if (ret) {
+		/* Don't return error for duplicate OPPs */
+		if (ret == -EBUSY)
+			ret = 0;
 		goto free_opp;
+	}
 
 	/* OPP to select on device suspend */
 	if (of_property_read_bool(np, "opp-suspend")) {