Thread (1 message) 1 message, 1 author, 2019-11-16
STALE2442d REVIEWED: 1 (0M)

[PATCH AUTOSEL 4.14 046/150] PM / Domains: Deal with multiple states but no governor in genpd

From: Sasha Levin <sashal@kernel.org>
Date: 2019-11-16 15:48:34
Also in: lkml, stable
Subsystem: driver core, kobjects, debugfs and sysfs, hibernation (aka software suspend, aka swsusp), power management core, suspend to ram, the rest · Maintainers: Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Linus Torvalds

From: Ulf Hansson <redacted>

[ Upstream commit 2c9b7f8772033cc8bafbd4eefe2ca605bf3eb094 ]

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 <redacted>
Reviewed-by: Lina Iyer <redacted>
Signed-off-by: Rafael J. Wysocki <redacted>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 c276ba1c0a19e..e811f24148897 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -369,6 +369,10 @@ 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;
 
@@ -1598,6 +1602,8 @@ 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);
-- 
2.20.1
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