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>

diff --git a/drivers/thermal/devfreq_cooling.c b/drivers/thermal/devfreq_cooling.c
index e99d0e026a53cac52d5e5a83f47ea8ade4b75294..4bf4ad58cffda0172a48138248f4b406790c58e8 100644 (file)
--- 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;
        }