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Commit 7f8538eb authored by Viresh Kumar's avatar Viresh Kumar Committed by Rafael J. Wysocki
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PM / OPP: Fix memory leak while adding duplicate OPPs 



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: default avatarViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: default avatarStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 7a308bb3

drivers/base/power/opp/core.c

+16 −2
Original line number Original line Diff line number Diff line
@@ -1067,6 +1067,16 @@ static bool _opp_supported_by_regulators(struct dev_pm_opp *opp, 
	return true;

	return true;

}

}





/*

 * Returns:

 * 0: On success. And appropriate error message for duplicate OPPs.

 * -EBUSY: For OPP with same freq/volt and is available. The callers of

 *  _opp_add() must return 0 if they receive -EBUSY from it. This is to make

 *  sure we don't print error messages unnecessarily if different parts of

 *  kernel try to initialize the OPP table.

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

 *  should be considered an error by the callers of _opp_add().

 */

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

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

	     struct opp_table *opp_table)

	     struct opp_table *opp_table)

{

{
@@ -1099,7 +1109,7 @@ int _opp_add(struct device *dev, struct dev_pm_opp *new_opp, 




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

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

		return opp->available &&

		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;

	new_opp->opp_table = opp_table;
@@ -1173,8 +1183,12 @@ int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt, 
	new_opp->dynamic = dynamic;

	new_opp->dynamic = dynamic;





	ret = _opp_add(dev, new_opp, opp_table);

	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;

		goto free_opp;

	}





	mutex_unlock(&opp_table_lock);

	mutex_unlock(&opp_table_lock);

drivers/base/power/opp/of.c

+5 −1
Original line number Original line Diff line number Diff line
@@ -327,8 +327,12 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np) 
		goto free_opp;

		goto free_opp;





	ret = _opp_add(dev, new_opp, opp_table);

	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;

		goto free_opp;

	}





	/* OPP to select on device suspend */

	/* OPP to select on device suspend */

	if (of_property_read_bool(np, "opp-suspend")) {

	if (of_property_read_bool(np, "opp-suspend")) {