PM / OPP: of_property_count_u32_elems() can return errors

of_property_count_u32_elems() will never return 0, but a -ve error value
of a positive count. And so the current !count check is wrong.

Also, a missing "opp-microvolt" property isn't a problem and so we need
to do of_find_property() separately to confirm that.

Fixes: 274659029c9d (PM / OPP: Add support to parse "operating-points-v2" bindings)
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
index 28cd75c535b047f2c4276fed4308fa8159491007..1194669c2bb554ac46b95c263fb5eb6f4e016942 100644 (file)
--- a/drivers/base/power/opp.c
+++ b/drivers/base/power/opp.c
@@ -892,10 +892,17 @@ static int opp_get_microvolt(struct dev_pm_opp *opp, struct device *dev)
        u32 microvolt[3] = {0};
        int count, ret;
 
-       count = of_property_count_u32_elems(opp->np, "opp-microvolt");
-       if (!count)
+       /* Missing property isn't a problem, but an invalid entry is */
+       if (!of_find_property(opp->np, "opp-microvolt", NULL))
                return 0;
 
+       count = of_property_count_u32_elems(opp->np, "opp-microvolt");
+       if (count < 0) {
+               dev_err(dev, "%s: Invalid opp-microvolt property (%d)\n",
+                       __func__, count);
+               return count;
+       }
+
        /* There can be one or three elements here */
        if (count != 1 && count != 3) {
                dev_err(dev, "%s: Invalid number of elements in opp-microvolt property (%d)\n",