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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
commit878ec1a9f0e5a6b344c12fdc349ec7cb036c2a42 (patch)
tree45152b99aa4c6814d244ca9e1de8579ea75869d2 /drivers/opp
parent25419de1b8dda24f3e02478b12b724a9b0cc4e78 (diff)
downloadlinux-878ec1a9f0e5a6b344c12fdc349ec7cb036c2a42.tar.bz2
PM / OPP: Fix shared OPP table support in dev_pm_opp_set_prop_name()
It should be fine to call dev_pm_opp_set_prop_name() 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_prop_name() 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_prop_name() is called for the same OPP table, dev_pm_opp_put_prop_name() 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.c25
1 files changed, 5 insertions, 20 deletions
diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 481affb783f3..86e8e2c1905f 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -1216,7 +1216,6 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_put_supported_hw);
struct opp_table *dev_pm_opp_set_prop_name(struct device *dev, const char *name)
{
struct opp_table *opp_table;
- int ret;
opp_table = dev_pm_opp_get_opp_table(dev);
if (!opp_table)
@@ -1225,26 +1224,17 @@ struct opp_table *dev_pm_opp_set_prop_name(struct device *dev, const char *name)
/* Make sure there are no concurrent readers while updating opp_table */
WARN_ON(!list_empty(&opp_table->opp_list));
- /* Do we already have a prop-name associated with opp_table? */
- if (opp_table->prop_name) {
- dev_err(dev, "%s: Already have prop-name %s\n", __func__,
- opp_table->prop_name);
- ret = -EBUSY;
- goto err;
- }
+ /* Another CPU that shares the OPP table has set the property ? */
+ if (opp_table->prop_name)
+ return opp_table;
opp_table->prop_name = kstrdup(name, GFP_KERNEL);
if (!opp_table->prop_name) {
- ret = -ENOMEM;
- goto err;
+ dev_pm_opp_put_opp_table(opp_table);
+ return ERR_PTR(-ENOMEM);
}
return opp_table;
-
-err:
- dev_pm_opp_put_opp_table(opp_table);
-
- return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(dev_pm_opp_set_prop_name);
@@ -1261,11 +1251,6 @@ void dev_pm_opp_put_prop_name(struct opp_table *opp_table)
/* Make sure there are no concurrent readers while updating opp_table */
WARN_ON(!list_empty(&opp_table->opp_list));
- if (!opp_table->prop_name) {
- pr_err("%s: Doesn't have a prop-name\n", __func__);
- return;
- }
-
kfree(opp_table->prop_name);
opp_table->prop_name = NULL;