From 2c9b7f8772033cc8bafbd4eefe2ca605bf3eb094 Mon Sep 17 00:00:00 2001
From: Ulf Hansson <ulf.hansson@linaro.org>
Date: Wed, 3 Oct 2018 16:38:15 +0200
Subject: [PATCH] PM / Domains: Deal with multiple states but no governor in genpd
Git-commit: 2c9b7f8772033cc8bafbd4eefe2ca605bf3eb094
Patch-mainline: v4.20-rc1
References: bsc#1051510

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>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/base/power/domain.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -339,6 +339,10 @@ static int genpd_power_off(struct generi
 			return -EAGAIN;
 	}
 
+	/* Default to shallowest state. */
+	if (!genpd->gov)
+		genpd->state_idx = 0;
+
 	if (genpd->power_off) {
 		int ret;
 
@@ -1512,6 +1516,8 @@ int pm_genpd_init(struct generic_pm_doma
 		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);