PM / Domains: Deal with multiple states but no governor in genpd

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.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Lina Iyer <ilina@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index e1bbddb02871..7f38a92b444a 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -467,6 +467,10 @@ 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;
 
@@ -1687,6 +1691,8 @@ 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);
         }
 
         device_initialize(&genpd->dev);