regulator: Optimise out noop voltage changes
If a consumer sets the same voltage range as is currently configured
for that consumer there's no need to run through setting the voltage
again. This pattern may occur with some CPUfreq implementations where
the same voltage range is used for multiple frequencies.
Reported-by: Saravana Kannan <[email protected]>
Signed-off-by: Mark Brown <[email protected]>
Signed-off-by: Liam Girdwood <[email protected]>
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index a12cba3..ab419f8 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1697,10 +1697,17 @@
int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV)
{
struct regulator_dev *rdev = regulator->rdev;
- int ret;
+ int ret = 0;
mutex_lock(&rdev->mutex);
+ /* If we're setting the same range as last time the change
+ * should be a noop (some cpufreq implementations use the same
+ * voltage for multiple frequencies, for example).
+ */
+ if (regulator->min_uV == min_uV && regulator->max_uV == max_uV)
+ goto out;
+
/* sanity check */
if (!rdev->desc->ops->set_voltage &&
!rdev->desc->ops->set_voltage_sel) {
