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From:   Ulf Hansson <ulf.hansson@linaro.org>
To:     "Rafael J . Wysocki" <rjw@rjwysocki.net>,
        Sudeep Holla <sudeep.holla@arm.com>,
        Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>,
        Mark Rutland <mark.rutland@arm.com>, linux-pm@vger.kernel.org
Cc:     Kevin Hilman <khilman@kernel.org>,
        Lina Iyer <ilina@codeaurora.org>,
        Lina Iyer <lina.iyer@linaro.org>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Stephen Boyd <sboyd@kernel.org>,
        Juri Lelli <juri.lelli@arm.com>,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        linux-arm-kernel@lists.infradead.org,
        linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v7 02/26] PM / Domains: Deal with multiple states but no governor in genpd
Date:   Thu, 12 Apr 2018 13:14:07 +0200
Message-Id: <1523531671-27491-3-git-send-email-ulf.hansson@linaro.org>
In-Reply-To: <1523531671-27491-1-git-send-email-ulf.hansson@linaro.org>
References: <1523531671-27491-1-git-send-email-ulf.hansson@linaro.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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@codeaurora.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.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 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