On 10/26/2016 12:22 AM, Chanwoo Choi wrote:
Hi,
On 2016년 10월 26일 10:25, Saravana Kannan wrote:
If the new governor fails to start, switch back to old governor so that the
devfreq state is not left in some weird limbo.
Signed-off-by: Saravana Kannan <[email protected]>
---
* Fixed typo in commit text
* Fixed potential NULL deref
drivers/devfreq/devfreq.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index bf3ea76..243253e 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -919,7 +919,7 @@ 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)
@@ -944,12 +944,17 @@ 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);
+ df->governor = prev_gov;
+ strncpy(df->governor_name, prev_gov->name, DEVFREQ_NAME_LEN);
+ df->governor->event_handler(df, DEVFREQ_GOV_START, NULL);
+ }
Sigh... looks like I added the changes to the index but forgot to commit
it before I sent the patch. Will send v3.
out:
mutex_unlock(&devfreq_list_lock);
Looks good to me.
But, how about using the 'prev_governor' instead of 'prev_gov'?
because the variable name of current governor is 'governor' instead of 'gov'.
I was trying to avoid wrapping lines too much. But this doesn't cause
any additional wraps. Done.
Reviewed-by: Chanwoo Choi <[email protected]>
Can you please review v3?
Thanks,
Saravana
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