thermal: devfreq: Check OPP for errors

It is possible for dev_pm_opp_find_freq_exact() to return errors. It was
all fine earlier as dev_pm_opp_get_voltage() had a check within it to
check for invalid OPPs, but dev_pm_opp_put() doesn't have any similar
checks and the callers need to make sure OPP is valid before calling
them.

Also update the later dev_warn_ratelimited() to not print the error
message as the OPP is guaranteed to be valid now.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/thermal/devfreq_cooling.c b/drivers/thermal/devfreq_cooling.c
index e99d0e026a53..4bf4ad58cffd 100644
--- a/drivers/thermal/devfreq_cooling.c
+++ b/drivers/thermal/devfreq_cooling.c
@@ -189,13 +189,19 @@ get_static_power(struct devfreq_cooling_device *dfc, unsigned long freq)
         if (PTR_ERR(opp) == -ERANGE)
                 opp = dev_pm_opp_find_freq_exact(dev, freq, false);
 
+        if (IS_ERR(opp)) {
+                dev_err_ratelimited(dev, "Failed to find OPP for frequency %lu: %ld\n",
+                                    freq, PTR_ERR(opp));
+                return 0;
+        }
+
         voltage = dev_pm_opp_get_voltage(opp) / 1000; /* mV */
         dev_pm_opp_put(opp);
 
         if (voltage == 0) {
                 dev_err_ratelimited(dev,
-                                    "Failed to get voltage for frequency %lu: %ld\n",
-                                    freq, IS_ERR(opp) ? PTR_ERR(opp) : 0);
+                                    "Failed to get voltage for frequency %lu\n",
+                                    freq);
                 return 0;
         }