| Message ID | 1477445160-990-1-git-send-email-skannan@codeaurora.org (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
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 <skannan@codeaurora.org> > --- > * 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); > + } > 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'. Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
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 <skannan@codeaurora.org> >> --- >> * 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 <cw00.choi@samsung.com> > Can you please review v3? Thanks, Saravana
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); + } out: mutex_unlock(&devfreq_list_lock);
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 <skannan@codeaurora.org> --- * Fixed typo in commit text * Fixed potential NULL deref drivers/devfreq/devfreq.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)