Dear Viresh,

On Fri, 22 Jul 2016 09:21:51 -0700 Viresh Kumar  wrote:

On 22-07-16, 20:42, Jisheng Zhang wrote:

quoted

 static int _set_opp_voltage(struct device *dev, struct regulator *reg,
 			    unsigned long u_volt, unsigned long u_volt_min,
 			    unsigned long u_volt_max)

@@ -586,9 +565,24 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
 		return -EINVAL;
 	}
 
-	clk = _get_opp_clk(dev);
-	if (IS_ERR(clk))
+	rcu_read_lock();
+
+	opp_table = _find_opp_table(dev);
+	if (IS_ERR(opp_table)) {
+		dev_err(dev, "%s: device opp doesn't exist\n", __func__);
+		rcu_read_unlock();
+		return PTR_ERR(opp_table);
+	}
+
+	clk = opp_table->clk;
+	if (IS_ERR(clk)) {
+		dev_err(dev, "%s: No clock available for the device\n",
+			__func__);
+		rcu_read_unlock();
 		return PTR_ERR(clk);
+	}
+
+	rcu_read_unlock();  

It is not _safe_ to use opp_table pointer after the rcu_read_unlock()

Oops, indeed. Thanks very much for pointing it out! Will fix it in v2, so
it seems we can only reduce the call of _find_opp_table to twice.

Thanks,
Jisheng