[PATCH v7 02/26] PM / Domains: Deal with multiple states but no governor in genpd

From: Ulf Hansson
Date: Thu Apr 12 2018 - 07:14:48 EST


A caller of pm_genpd_init() that provides some states for the genpd via the
->states pointer in the struct generic_pm_domain, should also provide a
governor. This because it's the job of the governor to pick a state that
satisfies the constraints.

Therefore, let's print a warning to inform the user about such bogus
configuration and avoid to bail out, by instead picking the shallowest
state before genpd invokes the ->power_off() callback.

Cc: Lina Iyer <ilina@xxxxxxxxxxxxxx>
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
---
drivers/base/power/domain.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index c2ef944..9aff79d 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -466,6 +466,10 @@ static int genpd_power_off(struct generic_pm_domain *genpd, bool one_dev_on,
return -EAGAIN;
}

+ /* Default to shallowest state. */
+ if (!genpd->gov)
+ genpd->state_idx = 0;
+
if (genpd->power_off) {
int ret;

@@ -1694,6 +1698,8 @@ int pm_genpd_init(struct generic_pm_domain *genpd,
ret = genpd_set_default_power_state(genpd);
if (ret)
return ret;
+ } else if (!gov) {
+ pr_warn("%s : no governor for states\n", genpd->name);
}

mutex_lock(&gpd_list_lock);
--
2.7.4