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| author |   Saravana Kannan <skannan@codeaurora.org> | 2019-03-11 15:36:30 +0530 |
|---|---|---|
| committer |   MyungJoo Ham <myungjoo.ham@samsung.com> | 2019-04-16 09:29:18 +0900 |
| commit | bc658bef97a70094d4347faab7cabf2f5267d03f (patch) | |
| tree | 8cf19e817e2b036c5bb0114ab4091355ba0ba644 /drivers/devfreq | |
| parent | PM / devfreq: tegra: remove unneeded variable (diff) | |
| download | linux-dev-bc658bef97a70094d4347faab7cabf2f5267d03f.tar.xz linux-dev-bc658bef97a70094d4347faab7cabf2f5267d03f.zip | |
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.
[Myungjoo: assume fatal on revert failure and set df->governor to NULL]
Signed-off-by: Sibi Sankar <sibis@codeaurora.org>
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Diffstat (limited to 'drivers/devfreq')
| -rw-r--r-- | drivers/devfreq/devfreq.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 428a1de81008..08dfcdc2ac58 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -1124,7 +1124,7 @@ 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_governor; ret = sscanf(buf, "%" __stringify(DEVFREQ_NAME_LEN) "s", str_governor); if (ret != 1) @@ -1153,12 +1153,24 @@ static ssize_t governor_store(struct device *dev, struct device_attribute *attr, goto out; } } + prev_governor = 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); + df->governor = prev_governor; + strncpy(df->governor_name, prev_governor->name, + DEVFREQ_NAME_LEN); + ret = df->governor->event_handler(df, DEVFREQ_GOV_START, NULL); + if (ret) { + dev_err(dev, + "%s: reverting to Governor %s failed (%d)\n", + __func__, df->governor_name, ret); + df->governor = NULL; + } + } out: mutex_unlock(&devfreq_list_lock); |