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    SubjectRe: [PATCH V2] Cpufreq: Make governor data on nonboot cpus across system suspend/resume
    Date
    On Saturday, November 16, 2013 11:36:24 PM Lan Tianyu wrote:
    > Currently, governor of nonboot cpus will be put to EXIT when system suspend.
    > Since all these cpus will be unplugged and the governor usage_count decreases
    > to zero. The governor data and its sysfs interfaces will be freed or released.
    > This makes user config of these governors loss during suspend and resume.
    >
    > This doesn't happen on the governor covering boot cpu because it isn't
    > unplugged during system suspend.
    >
    > To fix this issue, skipping governor exit during system suspend and check
    > policy governor data to determine whether the governor is really needed
    > to be initialized when do init. If not, return EALREADY to indicate the
    > governor has been initialized and should do nothing. __cpufreq_governor()
    > convert EALREADY to 0 as return value for INIT event since governor is
    > still under INIT state and can do START operation.
    >
    > Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
    > ---
    > Change since v1:
    > Change coding style.
    >
    > drivers/cpufreq/cpufreq.c | 10 +++++++---
    > drivers/cpufreq/cpufreq_governor.c | 13 ++++++++++++-
    > 2 files changed, 19 insertions(+), 4 deletions(-)
    >
    > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
    > index 02d534d..73ad593 100644
    > --- a/drivers/cpufreq/cpufreq.c
    > +++ b/drivers/cpufreq/cpufreq.c
    > @@ -1239,7 +1239,7 @@ static int __cpufreq_remove_dev_finish(struct device *dev,
    >
    > /* If cpu is last user of policy, free policy */
    > if (cpus == 1) {
    > - if (has_target()) {
    > + if (has_target() && !frozen) {
    > ret = __cpufreq_governor(policy,
    > CPUFREQ_GOV_POLICY_EXIT);
    > if (ret) {
    > @@ -1818,9 +1818,13 @@ static int __cpufreq_governor(struct cpufreq_policy *policy,
    > mutex_unlock(&cpufreq_governor_lock);
    > }
    >
    > - if (((event == CPUFREQ_GOV_POLICY_INIT) && ret) ||

    The inner parens are not necessary.

    > - ((event == CPUFREQ_GOV_POLICY_EXIT) && !ret))
    > + if ((event == CPUFREQ_GOV_POLICY_INIT) && ret) {

    Same here.

    > + module_put(policy->governor->owner);
    > + if (ret == -EALREADY)
    > + return 0;
    > + } else if ((event == CPUFREQ_GOV_POLICY_EXIT) && !ret) {

    Same here.

    > module_put(policy->governor->owner);
    > + }

    Can you please combine these checks with the checks made right after
    calling policy->governor->governor() as indicated by Viresh?

    Rafael



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