[03/13] cpufreq: davinci: call CPUFREQ_POSTCHANGE notfier in error cases

Message ID 6e65891cd3e33c5db94563a387832ae648ef0d8c.1371630975.git.viresh.kumar@linaro.org
State Accepted
Headers show

Commit Message

Viresh Kumar June 19, 2013, 8:52 a.m.
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.

Davinci driver was taking care of it but frequency isn't restored to freqs.old.

This patch fixes it.

Cc: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/cpufreq/davinci-cpufreq.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Sekhar Nori June 19, 2013, 8:58 a.m. | #1
On 6/19/2013 2:22 PM, Viresh Kumar wrote:
> 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.
> 
> Davinci driver was taking care of it but frequency isn't restored to freqs.old.
> 
> This patch fixes it.
> 
> Cc: Sekhar Nori <nsekhar@ti.com>
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

Looks good to me.

Acked-by: Sekhar Nori <nsekhar@ti.com>

Thanks,
Sekhar

Patch

diff --git a/drivers/cpufreq/davinci-cpufreq.c b/drivers/cpufreq/davinci-cpufreq.c
index c33c76c..551dd65 100644
--- a/drivers/cpufreq/davinci-cpufreq.c
+++ b/drivers/cpufreq/davinci-cpufreq.c
@@ -114,6 +114,9 @@  static int davinci_target(struct cpufreq_policy *policy,
 		pdata->set_voltage(idx);
 
 out:
+	if (ret)
+		freqs.new = freqs.old;
+
 	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
 
 	return ret;