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authorViresh Kumar <viresh.kumar@linaro.org>2018-05-22 16:38:08 +0530
committerViresh Kumar <viresh.kumar@linaro.org>2018-05-22 17:00:10 +0530
commit779b783cfaa726cbe35317ae2c1968c5496a3a03 (patch)
tree9e9242379d47b8dc8820528ff94f6ddb8916629c /drivers/opp
parent878ec1a9f0e5a6b344c12fdc349ec7cb036c2a42 (diff)
downloadlinux-779b783cfaa726cbe35317ae2c1968c5496a3a03.tar.bz2
PM / OPP: Fix shared OPP table support in dev_pm_opp_set_regulators()
It should be fine to call dev_pm_opp_set_regulators() for all possible CPUs, even if some of them share the OPP table as the caller may not be aware of sharing policy. Lets increment the reference count of the OPP table and return its pointer. The caller need to call dev_pm_opp_put_regulators() the same number of times later on to drop all the references. To avoid adding another counter to count how many times dev_pm_opp_set_regulators() is called for the same OPP table, dev_pm_opp_put_regulators() frees the resources on the very first call made to it, assuming that the caller would be calling it sequentially for all the CPUs. We can revisit that if that assumption is broken in the future. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Diffstat (limited to 'drivers/opp')
-rw-r--r--drivers/opp/core.c15
1 files changed, 6 insertions, 9 deletions
diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 86e8e2c1905f..780c89a49d18 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -1320,11 +1320,9 @@ struct opp_table *dev_pm_opp_set_regulators(struct device *dev,
goto err;
}
- /* Already have regulators set */
- if (opp_table->regulators) {
- ret = -EBUSY;
- goto err;
- }
+ /* Another CPU that shares the OPP table has set the regulators ? */
+ if (opp_table->regulators)
+ return opp_table;
opp_table->regulators = kmalloc_array(count,
sizeof(*opp_table->regulators),
@@ -1378,10 +1376,8 @@ void dev_pm_opp_put_regulators(struct opp_table *opp_table)
{
int i;
- if (!opp_table->regulators) {
- pr_err("%s: Doesn't have regulators set\n", __func__);
- return;
- }
+ if (!opp_table->regulators)
+ goto put_opp_table;
/* Make sure there are no concurrent readers while updating opp_table */
WARN_ON(!list_empty(&opp_table->opp_list));
@@ -1395,6 +1391,7 @@ void dev_pm_opp_put_regulators(struct opp_table *opp_table)
opp_table->regulators = NULL;
opp_table->regulator_count = 0;
+put_opp_table:
dev_pm_opp_put_opp_table(opp_table);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_put_regulators);