dev_pm_opp_set_rate() can now be called with freq = 0 inorder
to either drop performance or bandwidth votes or to disable
regulators on platforms which support them.
In such cases, a subsequent call to dev_pm_opp_set_rate() with
the same frequency ends up returning early because 'old_freq == freq'
Instead make it fall through and put back the dropped performance
and bandwidth votes and/or enable back the regulators.

Fixes: cd7ea582 ("opp: Make dev_pm_opp_set_rate() handle freq = 0 to drop performance votes")
Reported-by: Sajida Bhanu <redacted>
Signed-off-by: Rajendra Nayak <redacted>
---
 drivers/opp/core.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 0c8c74a..a994f30 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c

@@ -901,6 +901,9 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
 
        /* Return early if nothing to do */
        if (old_freq == freq) {
+               if (opp_table->required_opp_tables || opp_table->regulators ||
+                   opp_table->paths)
+                       goto skip_clk_only;

                dev_dbg(dev, "%s: old/new frequencies (%lu Hz) are same, nothing to do\n",
                        __func__, freq);
                ret = 0;

@@ -919,6 +922,7 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
                goto put_opp_table;
        }
 
+skip_clk_only:
        temp_freq = old_freq;
        old_opp = _find_freq_ceil(opp_table, &temp_freq);
        if (IS_ERR(old_opp)) {

@@ -954,8 +958,10 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
                                                 IS_ERR(old_opp) ? NULL : old_opp->supplies,
                                                 opp->supplies);
        } else {
+               ret = 0;
                /* Only frequency scaling */
-               ret = _generic_set_opp_clk_only(dev, clk, freq);
+               if (freq != old_freq)
+                       ret = _generic_set_opp_clk_only(dev, clk, freq);
        }