| Message ID | 1447799871-56374-5-git-send-email-lina.iyer@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 17 November 2015 at 23:37, Lina Iyer <lina.iyer@linaro.org> wrote: > From: Axel Haslam <ahaslam+renesas@baylibre.com> > > Now that the structures of genpd can support multiple state definitions, > add the logic in the governor to select the deepest possible state when > powering down. > > For this, create the new function power_down_ok_for_state which will test > if a particular state will not violate the devices and sub-domains > constraints. > > default_power_down_ok is modified to try each state starting from the > deepest until a valid state is found or there are no more states to test. > > the resulting state will be valid until there are latency or constraint > changes, thus, we can avoid looping every power_down, and use the cached > results instead. > > Signed-off-by: Axel Haslam <ahaslam+renesas@baylibre.com> > --- > drivers/base/power/domain_governor.c | 75 +++++++++++++++++++++--------------- > 1 file changed, 45 insertions(+), 30 deletions(-) Browsing the changes here and I think it looks good and quite trivial. I would therefore suggest that you fold this change into patch1 as it's where it really belongs. Can you please do that? > > diff --git a/drivers/base/power/domain_governor.c b/drivers/base/power/domain_governor.c > index b4984f5..ad69dc0 100644 > --- a/drivers/base/power/domain_governor.c > +++ b/drivers/base/power/domain_governor.c > @@ -98,7 +98,8 @@ static bool default_stop_ok(struct device *dev) > * > * This routine must be executed under the PM domain's lock. > */ > -static bool default_power_down_ok(struct dev_pm_domain *pd) > +static bool power_down_ok_for_state(struct dev_pm_domain *pd, > + unsigned int state) I suggest you re-name this function "__default_power_down_ok()" instead. > { > struct generic_pm_domain *genpd = pd_to_genpd(pd); > struct gpd_link *link; > @@ -106,31 +107,9 @@ static bool default_power_down_ok(struct dev_pm_domain *pd) > s64 min_off_time_ns; > s64 off_on_time_ns; > > - if (genpd->max_off_time_changed) { > - struct gpd_link *link; > + off_on_time_ns = genpd->states[state].power_off_latency_ns + > + genpd->states[state].power_on_latency_ns; > > - /* > - * We have to invalidate the cached results for the masters, so > - * use the observation that default_power_down_ok() is not > - * going to be called for any master until this instance > - * returns. > - */ > - list_for_each_entry(link, &genpd->slave_links, slave_node) > - link->master->max_off_time_changed = true; > - > - genpd->max_off_time_changed = false; > - genpd->cached_power_down_ok = false; > - genpd->max_off_time_ns = -1; > - } else { > - return genpd->cached_power_down_ok; > - } > - > - /* > - * Use the only available state, until multiple state support is added > - * to the governor. > - */ > - off_on_time_ns = genpd->states[0].power_off_latency_ns + > - genpd->states[0].power_on_latency_ns; > > min_off_time_ns = -1; > /* > @@ -193,8 +172,6 @@ static bool default_power_down_ok(struct dev_pm_domain *pd) > min_off_time_ns = constraint_ns; > } > > - genpd->cached_power_down_ok = true; > - > /* > * If the computed minimum device off time is negative, there are no > * latency constraints, so the domain can spend arbitrary time in the > @@ -207,14 +184,52 @@ static bool default_power_down_ok(struct dev_pm_domain *pd) > * The difference between the computed minimum subdomain or device off > * time and the time needed to turn the domain on is the maximum > * theoretical time this domain can spend in the "off" state. > - * Use the only available state, until multiple state support is added > - * to the governor. > */ > genpd->max_off_time_ns = min_off_time_ns - > - genpd->states[0].power_on_latency_ns; > + genpd->states[state].power_on_latency_ns; > return true; > } > > +static bool default_power_down_ok(struct dev_pm_domain *pd) > +{ > + struct generic_pm_domain *genpd = pd_to_genpd(pd); > + unsigned int last_state_idx = genpd->state_count - 1; > + struct gpd_link *link; > + bool retval = false; > + unsigned int i; > + > + /* > + * if there was no change on max_off_time, we can return the > + * cached value and we dont need to find a new target_state > + */ The related code speaks for itself, I think you can drop the above comment. > + if (!genpd->max_off_time_changed) > + return genpd->cached_power_down_ok; > + > + /* > + * We have to invalidate the cached results for the masters, so > + * use the observation that default_power_down_ok() is not > + * going to be called for any master until this instance > + * returns. > + */ > + list_for_each_entry(link, &genpd->slave_links, slave_node) > + link->master->max_off_time_changed = true; > + > + genpd->max_off_time_ns = -1; > + genpd->max_off_time_changed = false; > + > + /* find a state to power down to, starting from the deepest */ Please start sentence with an upper case letter and end it with a dot. > + for (i = 0; i < genpd->state_count; i++) { > + if (power_down_ok_for_state(pd, last_state_idx - i)) { > + genpd->state_idx = last_state_idx - i; > + retval = true; Instead of assigning a local copy "retval", I think you can assign genpd->cached_power_down_ok and later below just return its value. > + break; > + } > + } I think you should convert this to a while loop instead as I think it becomes easier to understand what goes on. > + > + genpd->cached_power_down_ok = retval; > + return retval; > +} > + > static bool always_on_power_down_ok(struct dev_pm_domain *domain) > { > return false; > -- > 2.1.4 > Kind regards Uffe
diff --git a/drivers/base/power/domain_governor.c b/drivers/base/power/domain_governor.c index b4984f5..ad69dc0 100644 --- a/drivers/base/power/domain_governor.c +++ b/drivers/base/power/domain_governor.c @@ -98,7 +98,8 @@ static bool default_stop_ok(struct device *dev) * * This routine must be executed under the PM domain's lock. */ -static bool default_power_down_ok(struct dev_pm_domain *pd) +static bool power_down_ok_for_state(struct dev_pm_domain *pd, + unsigned int state) { struct generic_pm_domain *genpd = pd_to_genpd(pd); struct gpd_link *link; @@ -106,31 +107,9 @@ static bool default_power_down_ok(struct dev_pm_domain *pd) s64 min_off_time_ns; s64 off_on_time_ns; - if (genpd->max_off_time_changed) { - struct gpd_link *link; + off_on_time_ns = genpd->states[state].power_off_latency_ns + + genpd->states[state].power_on_latency_ns; - /* - * We have to invalidate the cached results for the masters, so - * use the observation that default_power_down_ok() is not - * going to be called for any master until this instance - * returns. - */ - list_for_each_entry(link, &genpd->slave_links, slave_node) - link->master->max_off_time_changed = true; - - genpd->max_off_time_changed = false; - genpd->cached_power_down_ok = false; - genpd->max_off_time_ns = -1; - } else { - return genpd->cached_power_down_ok; - } - - /* - * Use the only available state, until multiple state support is added - * to the governor. - */ - off_on_time_ns = genpd->states[0].power_off_latency_ns + - genpd->states[0].power_on_latency_ns; min_off_time_ns = -1; /* @@ -193,8 +172,6 @@ static bool default_power_down_ok(struct dev_pm_domain *pd) min_off_time_ns = constraint_ns; } - genpd->cached_power_down_ok = true; - /* * If the computed minimum device off time is negative, there are no * latency constraints, so the domain can spend arbitrary time in the @@ -207,14 +184,52 @@ static bool default_power_down_ok(struct dev_pm_domain *pd) * The difference between the computed minimum subdomain or device off * time and the time needed to turn the domain on is the maximum * theoretical time this domain can spend in the "off" state. - * Use the only available state, until multiple state support is added - * to the governor. */ genpd->max_off_time_ns = min_off_time_ns - - genpd->states[0].power_on_latency_ns; + genpd->states[state].power_on_latency_ns; return true; } +static bool default_power_down_ok(struct dev_pm_domain *pd) +{ + struct generic_pm_domain *genpd = pd_to_genpd(pd); + unsigned int last_state_idx = genpd->state_count - 1; + struct gpd_link *link; + bool retval = false; + unsigned int i; + + /* + * if there was no change on max_off_time, we can return the + * cached value and we dont need to find a new target_state + */ + if (!genpd->max_off_time_changed) + return genpd->cached_power_down_ok; + + /* + * We have to invalidate the cached results for the masters, so + * use the observation that default_power_down_ok() is not + * going to be called for any master until this instance + * returns. + */ + list_for_each_entry(link, &genpd->slave_links, slave_node) + link->master->max_off_time_changed = true; + + genpd->max_off_time_ns = -1; + genpd->max_off_time_changed = false; + + /* find a state to power down to, starting from the deepest */ + for (i = 0; i < genpd->state_count; i++) { + if (power_down_ok_for_state(pd, last_state_idx - i)) { + genpd->state_idx = last_state_idx - i; + retval = true; + break; + } + } + + genpd->cached_power_down_ok = retval; + return retval; +} + static bool always_on_power_down_ok(struct dev_pm_domain *domain) { return false;