PRECHANGE and POSTCHANGE notifiers must be called in groups, i.e either both should be called or both shouldn't be.
In case we have started PRECHANGE notifier and found an error, we must call POSTCHANGE notifier with freqs.new = freqs.old to guarantee that sequence of calling notifiers is complete.
This patch fixes it.
This also moves PRECHANGE notifier down so that we call it just before starting frequency transition.
Cc: Shawn Guo shawn.guo@linaro.org Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/cpufreq/imx6q-cpufreq.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c index b78bc35..e37cdae 100644 --- a/drivers/cpufreq/imx6q-cpufreq.c +++ b/drivers/cpufreq/imx6q-cpufreq.c @@ -68,8 +68,6 @@ static int imx6q_set_target(struct cpufreq_policy *policy, if (freqs.old == freqs.new) return 0;
- cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); - rcu_read_lock(); opp = opp_find_freq_ceil(cpu_dev, &freq_hz); if (IS_ERR(opp)) { @@ -86,13 +84,16 @@ static int imx6q_set_target(struct cpufreq_policy *policy, freqs.old / 1000, volt_old / 1000, freqs.new / 1000, volt / 1000);
+ cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); + /* scaling up? scale voltage before frequency */ if (freqs.new > freqs.old) { ret = regulator_set_voltage_tol(arm_reg, volt, 0); if (ret) { dev_err(cpu_dev, "failed to scale vddarm up: %d\n", ret); - return ret; + freqs.new = freqs.old; + goto post_notify; }
/* @@ -145,15 +146,18 @@ static int imx6q_set_target(struct cpufreq_policy *policy, if (ret) { dev_err(cpu_dev, "failed to set clock rate: %d\n", ret); regulator_set_voltage_tol(arm_reg, volt_old, 0); - return ret; + freqs.new = freqs.old; + goto post_notify; }
/* scaling down? scale voltage after frequency */ if (freqs.new < freqs.old) { ret = regulator_set_voltage_tol(arm_reg, volt, 0); - if (ret) + if (ret) { dev_warn(cpu_dev, "failed to scale vddarm down: %d\n", ret); + ret = 0; + }
if (freqs.old == FREQ_1P2_GHZ / 1000) { regulator_set_voltage_tol(pu_reg, @@ -163,9 +167,10 @@ static int imx6q_set_target(struct cpufreq_policy *policy, } }
+post_notify: cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
- return 0; + return ret; }
static int imx6q_cpufreq_init(struct cpufreq_policy *policy)