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>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/cpufreq/omap-cpufreq.c b/drivers/cpufreq/omap-cpufreq.c
index 1f3417a8322d..97102b05843f 100644
--- 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);
         }