netdev - [RFC 8/8] thermal: Stop polling DISABLED thermal devices

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Message-Id: <20200407174926.23971-9-andrzej.p@collabora.com>
Date:   Tue,  7 Apr 2020 19:49:26 +0200
From:   Andrzej Pietrasiewicz <andrzej.p@...labora.com>
To:     linux-pm@...r.kernel.org
Cc:     Zhang Rui <rui.zhang@...el.com>,
        "Rafael J . Wysocki" <rjw@...ysocki.net>,
        Len Brown <lenb@...nel.org>, Jiri Pirko <jiri@...lanox.com>,
        Ido Schimmel <idosch@...lanox.com>,
        "David S . Miller" <davem@...emloft.net>,
        Peter Kaestle <peter@...e.net>,
        Darren Hart <dvhart@...radead.org>,
        Andy Shevchenko <andy@...radead.org>,
        Support Opensource <support.opensource@...semi.com>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Amit Kucheria <amit.kucheria@...durent.com>,
        Shawn Guo <shawnguo@...nel.org>,
        Sascha Hauer <s.hauer@...gutronix.de>,
        Pengutronix Kernel Team <kernel@...gutronix.de>,
        Fabio Estevam <festevam@...il.com>,
        NXP Linux Team <linux-imx@....com>,
        Allison Randal <allison@...utok.net>,
        Enrico Weigelt <info@...ux.net>,
        Gayatri Kammela <gayatri.kammela@...el.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        linux-acpi@...r.kernel.org, netdev@...r.kernel.org,
        platform-driver-x86@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, kernel@...labora.com,
        Andrzej Pietrasiewicz <andrzej.p@...labora.com>
Subject: [RFC 8/8] thermal: Stop polling DISABLED thermal devices

Polling DISABLED devices is not desired, as all such "disabled" devices
are meant to be handled by userspace.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@...labora.com>
---
 drivers/thermal/thermal_core.c | 26 ++++++++++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index aae2b049d45c..f74b7a792be7 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -305,13 +305,32 @@ static void thermal_zone_device_set_polling(struct thermal_zone_device *tz,
 		cancel_delayed_work(&tz->poll_queue);
 }
 
+static bool should_stop_polling(struct thermal_zone_device *tz)
+{
+	enum thermal_device_mode mode;
+	int result;
+
+	if (!tz->ops->get_mode)
+		return false;
+
+	result = tz->ops->get_mode(tz, &mode);
+	if (result)
+		return false;
+
+	return mode == THERMAL_DEVICE_DISABLED;
+}
+
 static void monitor_thermal_zone(struct thermal_zone_device *tz)
 {
+	bool stop;
+
+	stop = should_stop_polling(tz);
+
 	mutex_lock(&tz->lock);
 
-	if (tz->passive)
+	if (!stop && tz->passive)
 		thermal_zone_device_set_polling(tz, tz->passive_delay);
-	else if (tz->polling_delay)
+	else if (!stop && tz->polling_delay)
 		thermal_zone_device_set_polling(tz, tz->polling_delay);
 	else
 		thermal_zone_device_set_polling(tz, 0);
@@ -500,6 +519,9 @@ void thermal_zone_device_update(struct thermal_zone_device *tz,
 {
 	int count;
 
+	if (should_stop_polling(tz))
+		return;
+
 	if (atomic_read(&in_suspend))
 		return;
 
-- 
2.17.1