linux-kernel - [PATCH 13/14] PM: domains: Measure power-on/off latencies in genpd based on a governor

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Date:   Wed, 11 May 2022 16:57:03 +0200
From:   Ulf Hansson <ulf.hansson@...aro.org>
To:     "Rafael J . Wysocki" <rafael@...nel.org>, linux-pm@...r.kernel.org
Cc:     "Rafael J . Wysocki" <rjw@...ysocki.net>,
        Geert Uytterhoeven <geert+renesas@...der.be>,
        Maulik Shah <quic_mkshah@...cinc.com>,
        Gabriel Fernandez <gabriel.fernandez@...s.st.com>,
        Alexandre Torgue <alexandre.torgue@...s.st.com>,
        Dmitry Osipenko <digetx@...il.com>,
        Kevin Hilman <khilman@...nel.org>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: [PATCH 13/14] PM: domains: Measure power-on/off latencies in genpd based on a governor

The measurements of the power-on|off latencies in genpd for a PM domain are
superfluous, unless the corresponding genpd has a governor assigned to it,
which would make use of the data.

Therefore, let's improve the behaviour in genpd by making the measurements
conditional, based upon if there's a governor assigned.

Signed-off-by: Ulf Hansson <ulf.hansson@...aro.org>
---
 drivers/base/power/domain.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index a7de5fb8f073..83b073cdd0ed 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -509,6 +509,7 @@ static int _genpd_power_on(struct generic_pm_domain *genpd, bool timed)
 	if (!genpd->power_on)
 		goto out;
 
+	timed = timed && genpd->gd;
 	if (!timed) {
 		ret = genpd->power_on(genpd);
 		if (ret)
@@ -527,8 +528,7 @@ static int _genpd_power_on(struct generic_pm_domain *genpd, bool timed)
 		goto out;
 
 	genpd->states[state_idx].power_on_latency_ns = elapsed_ns;
-	if (genpd->gd)
-		genpd->gd->max_off_time_changed = true;
+	genpd->gd->max_off_time_changed = true;
 	pr_debug("%s: Power-%s latency exceeded, new value %lld ns\n",
 		 genpd->name, "on", elapsed_ns);
 
@@ -559,6 +559,7 @@ static int _genpd_power_off(struct generic_pm_domain *genpd, bool timed)
 	if (!genpd->power_off)
 		goto out;
 
+	timed = timed && genpd->gd;
 	if (!timed) {
 		ret = genpd->power_off(genpd);
 		if (ret)
@@ -577,8 +578,7 @@ static int _genpd_power_off(struct generic_pm_domain *genpd, bool timed)
 		goto out;
 
 	genpd->states[state_idx].power_off_latency_ns = elapsed_ns;
-	if (genpd->gd)
-		genpd->gd->max_off_time_changed = true;
+	genpd->gd->max_off_time_changed = true;
 	pr_debug("%s: Power-%s latency exceeded, new value %lld ns\n",
 		 genpd->name, "off", elapsed_ns);
 
-- 
2.25.1