OPP: Use a single mechanism to free the OPP table
Currently there are two separate ways to free the OPP table based on how
it is created in the first place.
We call _dev_pm_opp_remove_table() to free the static and/or dynamic
OPP, OPP list devices, etc. This is done for the case where the OPP
table is added while initializing the OPPs, like via the path
dev_pm_opp_of_add_table().
We also call dev_pm_opp_put_opp_table() in some cases which eventually
frees the OPP table structure once the reference count reaches 0. This
is used by the first case as well as other cases like
dev_pm_opp_set_regulators() where the OPPs aren't necessarily
initialized at this point.
This whole thing is a bit unclear and messy and obstruct any further
cleanup/fixup of OPP core.
This patch tries to streamline this by keeping a single path for OPP
table destruction, i.e. dev_pm_opp_put_opp_table().
All the cleanup happens in _opp_table_kref_release() now after the
reference count reaches 0. _dev_pm_opp_remove_table() is removed as it
isn't required anymore.
We don't drop the reference to the OPP table after creating it from
_of_add_opp_table_v{1|2}() anymore and the same is dropped only when we
try to remove them.
Tested-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 2319ad4..d3e33fd 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -867,23 +867,24 @@ struct opp_table *dev_pm_opp_get_opp_table_indexed(struct device *dev,
static void _opp_table_kref_release(struct kref *kref)
{
struct opp_table *opp_table = container_of(kref, struct opp_table, kref);
- struct opp_device *opp_dev;
+ struct opp_device *opp_dev, *temp;
/* Release clk */
if (!IS_ERR(opp_table->clk))
clk_put(opp_table->clk);
- /*
- * No need to take opp_table->lock here as we are guaranteed that no
- * references to the OPP table are taken at this point.
- */
- opp_dev = list_first_entry(&opp_table->dev_list, struct opp_device,
- node);
+ WARN_ON(!list_empty(&opp_table->opp_list));
- _remove_opp_dev(opp_dev, opp_table);
+ list_for_each_entry_safe(opp_dev, temp, &opp_table->dev_list, node) {
+ /*
+ * The OPP table is getting removed, drop the performance state
+ * constraints.
+ */
+ if (opp_table->genpd_performance_state)
+ dev_pm_genpd_set_performance_state((struct device *)(opp_dev->dev), 0);
- /* dev_list must be empty now */
- WARN_ON(!list_empty(&opp_table->dev_list));
+ _remove_opp_dev(opp_dev, opp_table);
+ }
mutex_destroy(&opp_table->lock);
list_del(&opp_table->node);
@@ -1758,33 +1759,6 @@ int dev_pm_opp_unregister_notifier(struct device *dev,
}
EXPORT_SYMBOL(dev_pm_opp_unregister_notifier);
-/*
- * Free OPPs either created using static entries present in DT.
- */
-void _dev_pm_opp_remove_table(struct opp_table *opp_table, struct device *dev)
-{
- /* Protect dev_list */
- mutex_lock(&opp_table->lock);
-
- /* Find if opp_table manages a single device */
- if (list_is_singular(&opp_table->dev_list)) {
- /* Free static OPPs */
- _put_opp_list_kref(opp_table);
-
- /*
- * The OPP table is getting removed, drop the performance state
- * constraints.
- */
- if (opp_table->genpd_performance_state)
- dev_pm_genpd_set_performance_state(dev, 0);
- } else {
- _put_opp_list_kref(opp_table);
- _remove_opp_dev(_find_opp_dev(dev, opp_table), opp_table);
- }
-
- mutex_unlock(&opp_table->lock);
-}
-
void _dev_pm_opp_find_and_remove_table(struct device *dev)
{
struct opp_table *opp_table;
@@ -1802,8 +1776,12 @@ void _dev_pm_opp_find_and_remove_table(struct device *dev)
return;
}
- _dev_pm_opp_remove_table(opp_table, dev);
+ _put_opp_list_kref(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);
}
