Commit 922ff075 authored by Viresh Kumar's avatar Viresh Kumar
Browse files

opp: Don't drop reference for an OPP table that was never parsed 



dev_pm_opp_remove_table() should drop a reference to the OPP table only
if the DT OPP table was parsed earlier with a call to
dev_pm_opp_of_add_table() earlier. Else it may end up dropping the
reference to the OPP table, which was added as a result of other calls
like dev_pm_opp_set_clkname(). And would hence result in undesirable
behavior later on when caller would try to free the resource again.

Fixes: 03758d60 ("opp: Replace list_kref with a local counter")
Reported-by: default avatarNaresh Kamboju <naresh.kamboju@linaro.org>
Reported-by: default avatarAnders Roxell <anders.roxell@linaro.org>
Tested-by: default avatarNaresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
parent 9123e3a7

drivers/opp/core.c

+16 −6
Original line number Diff line number Diff line
@@ -1291,13 +1291,19 @@ void dev_pm_opp_remove(struct device *dev, unsigned long freq) 
}

EXPORT_SYMBOL_GPL(dev_pm_opp_remove);



void _opp_remove_all_static(struct opp_table *opp_table)

bool _opp_remove_all_static(struct opp_table *opp_table)

{

	struct dev_pm_opp *opp, *tmp;

	bool ret = true;



	mutex_lock(&opp_table->lock);



	if (!opp_table->parsed_static_opps || --opp_table->parsed_static_opps)

	if (!opp_table->parsed_static_opps) {

		ret = false;

		goto unlock;

	}



	if (--opp_table->parsed_static_opps)

		goto unlock;



	list_for_each_entry_safe(opp, tmp, &opp_table->opp_list, node) {
@@ -1307,6 +1313,8 @@ void _opp_remove_all_static(struct opp_table *opp_table) 


unlock:

	mutex_unlock(&opp_table->lock);



	return ret;

}



/**
@@ -2409,12 +2417,14 @@ void _dev_pm_opp_find_and_remove_table(struct device *dev) 
		return;

	}



	_opp_remove_all_static(opp_table);



	/* Drop reference taken by _find_opp_table() */

	/*

	 * Drop the extra reference only if the OPP table was successfully added

	 * with dev_pm_opp_of_add_table() earlier.

	 **/

	if (_opp_remove_all_static(opp_table))

		dev_pm_opp_put_opp_table(opp_table);



	/* Drop reference taken while the OPP table was added */

	/* Drop reference taken by _find_opp_table() */

	dev_pm_opp_put_opp_table(opp_table);

}

drivers/opp/opp.h

+1 −1
Original line number Diff line number Diff line
@@ -212,7 +212,7 @@ struct opp_table { 


/* Routines internal to opp core */

void dev_pm_opp_get(struct dev_pm_opp *opp);

void _opp_remove_all_static(struct opp_table *opp_table);

bool _opp_remove_all_static(struct opp_table *opp_table);

void _get_opp_table_kref(struct opp_table *opp_table);

int _get_opp_count(struct opp_table *opp_table);

struct opp_table *_find_opp_table(struct device *dev);

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