From 5d1169198d97ac161bcac8b1faff25d4df545ffd Mon Sep 17 00:00:00 2001 From: Saravana Kannan Date: Mon, 24 Oct 2016 16:35:05 -0700 Subject: PM / devfreq: Restart previous governor if new governor fails to start If the new governor fails to start, switch back to old governor so that the devfreq state is not left in some weird limbo. Change-Id: I7cf1e6ceb63d27ce08b2d17b97a9844d257464ce Signed-off-by: Saravana Kannan --- drivers/devfreq/devfreq.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index bc1c5f6dd4bd..844a8ad666a9 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -806,7 +806,7 @@ static ssize_t governor_store(struct device *dev, struct device_attribute *attr, struct devfreq *df = to_devfreq(dev); int ret; char str_governor[DEVFREQ_NAME_LEN + 1]; - struct devfreq_governor *governor; + const struct devfreq_governor *governor, *prev_gov; ret = sscanf(buf, "%" __stringify(DEVFREQ_NAME_LEN) "s", str_governor); if (ret != 1) @@ -831,12 +831,21 @@ static ssize_t governor_store(struct device *dev, struct device_attribute *attr, goto out; } } + prev_gov = df->governor; df->governor = governor; strncpy(df->governor_name, governor->name, DEVFREQ_NAME_LEN); ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL); - if (ret) + if (ret) { dev_warn(dev, "%s: Governor %s not started(%d)\n", __func__, df->governor->name, ret); + if (prev_gov) { + df->governor = prev_gov; + strncpy(df->governor_name, prev_gov->name, + DEVFREQ_NAME_LEN); + df->governor->event_handler(df, DEVFREQ_GOV_START, + NULL); + } + } out: mutex_unlock(&devfreq_list_lock); -- cgit v1.2.3