From: Viresh Kumar viresh.kumar@linaro.org
[ Upstream commit 922ff0759a16299e24cacfc981ac07914d8f1826 ]
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: 03758d60265c ("opp: Replace list_kref with a local counter") Reported-by: Naresh Kamboju naresh.kamboju@linaro.org Reported-by: Anders Roxell anders.roxell@linaro.org Tested-by: Naresh Kamboju naresh.kamboju@linaro.org Signed-off-by: Viresh Kumar viresh.kumar@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/opp/core.c | 22 ++++++++++++++++------ drivers/opp/opp.h | 2 +- 2 files changed, 17 insertions(+), 7 deletions(-)
diff --git a/drivers/opp/core.c b/drivers/opp/core.c index 8c90f78717723..91dcad982d362 100644 --- a/drivers/opp/core.c +++ b/drivers/opp/core.c @@ -1265,13 +1265,19 @@ 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) { @@ -1281,6 +1287,8 @@ void _opp_remove_all_static(struct opp_table *opp_table)
unlock: mutex_unlock(&opp_table->lock); + + return ret; }
/** @@ -2382,13 +2390,15 @@ void _dev_pm_opp_find_and_remove_table(struct device *dev) return; }
- _opp_remove_all_static(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 by _find_opp_table() */ dev_pm_opp_put_opp_table(opp_table); - - /* Drop reference taken while the OPP table was added */ - dev_pm_opp_put_opp_table(opp_table); }
/** diff --git a/drivers/opp/opp.h b/drivers/opp/opp.h index e51646ff279eb..c3fcd571e446d 100644 --- a/drivers/opp/opp.h +++ b/drivers/opp/opp.h @@ -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);