cpufreq: OMAP: use RCU locks around usage of OPP

OPP pointer is RCU protected, hence after finding it, de-reference
also should be protected with the same RCU context else the OPP
pointer may become invalid.

Reported-by: Alexander Holler <holler@ahsoftware.de>
Tested-by: Alexander Holler <holler@ahsoftware.de>
Acked-by: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/omap-cpufreq.c b/drivers/cpufreq/omap-cpufreq.c
index 1f3417a8322dfe8b0ca773873e058f7eb3a6c283..97102b05843fa580435ae0ae5b872d9467b577df 100644 (file)
--- a/drivers/cpufreq/omap-cpufreq.c
+++ b/drivers/cpufreq/omap-cpufreq.c
@@ -110,13 +110,16 @@ static int omap_target(struct cpufreq_policy *policy,
        freq = ret;
 
        if (mpu_reg) {
+               rcu_read_lock();
                opp = opp_find_freq_ceil(mpu_dev, &freq);
                if (IS_ERR(opp)) {
+                       rcu_read_unlock();
                        dev_err(mpu_dev, "%s: unable to find MPU OPP for %d\n",
                                __func__, freqs.new);
                        return -EINVAL;
                }
                volt = opp_get_voltage(opp);
+               rcu_read_unlock();
                tol = volt * OPP_TOLERANCE / 100;
                volt_old = regulator_get_voltage(mpu_reg);
        }