[PATCH V3 05/16] PM / OPP: Allocate dev_opp from _add_device_opp()

Viresh Kumar
2015-07-29T10:53:58Z

There is no need to complicate _opp_add_dynamic() with allocation of
dev_opp as well. Allocate it from _add_device_opp() instead.

Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
drivers/base/power/opp.c | 50 ++++++++++++++++++++++++++----------------------
1 file changed, 27 insertions(+), 23 deletions(-)

diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
index 7895fdd64192..28d70c9f86ed 100644
--- a/drivers/base/power/opp.c
+++ b/drivers/base/power/opp.c
@@ -408,11 +408,11 @@ struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_floor);

/**
- * _add_device_opp() - Allocate a new device OPP table
+ * _add_device_opp() - Find device OPP table or allocate a new one
* @dev: device for which we do this operation
*
- * New device node which uses OPPs - used when multiple devices with OPP tables
- * are maintained.
+ * It tries to find an existing table first, if it couldn't find one, it
+ * allocates a new OPP table and returns that.
*
* Return: valid device_opp pointer if success, else NULL.
*/
@@ -420,6 +420,11 @@ static struct device_opp *_add_device_opp(struct device *dev)
{
struct device_opp *dev_opp;

+ /* Check for existing list for 'dev' first */
+ dev_opp = _find_device_opp(dev);
+ if (!IS_ERR(dev_opp))
+ return dev_opp;
+
/*
* Allocate a new device OPP table. In the infrequent case where a new
* device is needed to be added, we pay this penalty.
@@ -575,7 +580,7 @@ EXPORT_SYMBOL_GPL(dev_pm_opp_remove);
static int _opp_add_dynamic(struct device *dev, unsigned long freq,
long u_volt, bool dynamic)
{
- struct device_opp *dev_opp = NULL;
+ struct device_opp *dev_opp;
struct dev_pm_opp *opp, *new_opp;
struct list_head *head;
int ret;
@@ -592,19 +597,11 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq,
new_opp->rate = freq;
new_opp->u_volt = u_volt;
new_opp->available = true;
- new_opp->dynamic = dynamic;
-
- /* Check for existing list for 'dev' */
- dev_opp = _find_device_opp(dev);
- if (IS_ERR(dev_opp)) {
- dev_opp = _add_device_opp(dev);
- if (!dev_opp) {
- ret = -ENOMEM;
- goto free_opp;
- }

- head = &dev_opp->opp_list;
- goto list_add;
+ dev_opp = _add_device_opp(dev);
+ if (!dev_opp) {
+ ret = -ENOMEM;
+ goto free_opp;
}

/*
@@ -612,15 +609,22 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq,
* and discard if already present
*/
head = &dev_opp->opp_list;
+
+ /*
+ * Need to use &dev_opp->opp_list in the condition part of the 'for'
+ * loop, don't replace it with head otherwise it will become an infinite
+ * loop.
+ */
list_for_each_entry_rcu(opp, &dev_opp->opp_list, node) {
- if (new_opp->rate <= opp->rate)
- break;
- else
+ if (new_opp->rate > opp->rate) {
head = &opp->node;
- }
+ continue;
+ }
+
+ if (new_opp->rate < opp->rate)
+ break;

- /* Duplicate OPPs ? */
- if (new_opp->rate == opp->rate) {
+ /* Duplicate OPPs */
ret = opp->available && new_opp->u_volt == opp->u_volt ?
0 : -EEXIST;

@@ -630,7 +634,7 @@ static int _opp_add_dynamic(struct device *dev, unsigned long freq,
goto free_opp;
}

-list_add:
+ new_opp->dynamic = dynamic;
new_opp->dev_opp = dev_opp;
list_add_rcu(&new_opp->node, head);
mutex_unlock(&dev_opp_list_lock);
--
2.4.0