diff options
| author |   Viresh Kumar <viresh.kumar@linaro.org> | 2020-08-31 13:03:06 +0530 |
|---|---|---|
| committer | Viresh Kumar <viresh.kumar@linaro.org> | 2020-08-31 14:49:47 +0530 |
| commit | 922ff0759a16299e24cacfc981ac07914d8f1826 (patch) | |
| tree | f11160f107302a8d10084606450abfafcc0fd2ed /drivers/opp | |
| parent | Linux 5.9-rc1 (diff) | |
| download | linux-dev-922ff0759a16299e24cacfc981ac07914d8f1826.tar.xz linux-dev-922ff0759a16299e24cacfc981ac07914d8f1826.zip | |
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: 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>
Diffstat (limited to 'drivers/opp')
| -rw-r--r-- | drivers/opp/core.c | 22 | ||||
| -rw-r--r-- | 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 9d7fb45b1786..31ce5d19ee9e 100644 --- a/drivers/opp/core.c +++ b/drivers/opp/core.c @@ -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; } /** @@ -2409,13 +2417,15 @@ 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 e51646ff279e..c3fcd571e446 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); |