linux-kernel - [PATCH v4 1/2] thermal: rcar_gen3

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Message-ID: <20190424051145.23072-2-jiada_wang@mentor.com>
Date:   Wed, 24 Apr 2019 14:11:44 +0900
From:   Jiada Wang <jiada_wang@...tor.com>
To:     <rui.zhang@...el.com>, <edubezval@...il.com>,
        <daniel.lezcano@...aro.org>
CC:     <linux-pm@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <jiada_wang@...tor.com>, <horms+renesas@...ge.net.au>,
        <niklas.soderlund+renesas@...natech.se>, <geert+renesas@...der.be>,
        <sergei.shtylyov@...entembedded.com>,
        <marek.vasut+renesas@...il.com>,
        <kuninori.morimoto.gx@...esas.com>, <hien.dang.eb@...esas.com>,
        <fabrizio.castro@...renesas.com>, <dien.pham.ry@...esas.com>,
        <biju.das@...renesas.com>, <erosca@...adit-jv.com>,
        <george_davis@...tor.com>, <joshua_frkuska@...tor.com>
Subject: [PATCH v4 1/2] thermal: rcar_gen3_thermal: fix interrupt type

Currently IRQF_SHARED type interrupt line is allocated, but it
is not appropriate, as the interrupt line isn't shared between
different devices, instead IRQF_ONESHOT is the proper type.

By changing interrupt type to IRQF_ONESHOT, now irq handler is
no longer needed, as clear of interrupt status can be done in
threaded interrupt context.

Because IRQF_ONESHOT type interrupt line is kept disabled until
the threaded handler has been run, so there is no need to protect
read/write of REG_GEN3_IRQSTR with lock.

Fixes: 7d4b269776ec6 ("enable hardware interrupts for trip points")
Signed-off-by: Jiada Wang <jiada_wang@...tor.com>
---
 drivers/thermal/rcar_gen3_thermal.c | 38 +++++------------------------
 1 file changed, 6 insertions(+), 32 deletions(-)

diff --git a/drivers/thermal/rcar_gen3_thermal.c b/drivers/thermal/rcar_gen3_thermal.c
index 88fa41cf16e8..065e16f53285 100644
--- a/drivers/thermal/rcar_gen3_thermal.c
+++ b/drivers/thermal/rcar_gen3_thermal.c
@@ -14,7 +14,6 @@
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
-#include <linux/spinlock.h>
 #include <linux/sys_soc.h>
 #include <linux/thermal.h>
 
@@ -82,7 +81,6 @@ struct rcar_gen3_thermal_tsc {
 struct rcar_gen3_thermal_priv {
 	struct rcar_gen3_thermal_tsc *tscs[TSC_MAX_NUM];
 	unsigned int num_tscs;
-	spinlock_t lock; /* Protect interrupts on and off */
 	void (*thermal_init)(struct rcar_gen3_thermal_tsc *tsc);
 };
 
@@ -232,38 +230,16 @@ static irqreturn_t rcar_gen3_thermal_irq(int irq, void *data)
 {
 	struct rcar_gen3_thermal_priv *priv = data;
 	u32 status;
-	int i, ret = IRQ_HANDLED;
+	int i;
 
-	spin_lock(&priv->lock);
 	for (i = 0; i < priv->num_tscs; i++) {
 		status = rcar_gen3_thermal_read(priv->tscs[i], REG_GEN3_IRQSTR);
 		rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQSTR, 0);
 		if (status)
-			ret = IRQ_WAKE_THREAD;
+			thermal_zone_device_update(priv->tscs[i]->zone,
+						   THERMAL_EVENT_UNSPECIFIED);
 	}
 
-	if (ret == IRQ_WAKE_THREAD)
-		rcar_thermal_irq_set(priv, false);
-
-	spin_unlock(&priv->lock);
-
-	return ret;
-}
-
-static irqreturn_t rcar_gen3_thermal_irq_thread(int irq, void *data)
-{
-	struct rcar_gen3_thermal_priv *priv = data;
-	unsigned long flags;
-	int i;
-
-	for (i = 0; i < priv->num_tscs; i++)
-		thermal_zone_device_update(priv->tscs[i]->zone,
-					   THERMAL_EVENT_UNSPECIFIED);
-
-	spin_lock_irqsave(&priv->lock, flags);
-	rcar_thermal_irq_set(priv, true);
-	spin_unlock_irqrestore(&priv->lock, flags);
-
 	return IRQ_HANDLED;
 }
 
@@ -371,8 +347,6 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
 	if (soc_device_match(r8a7795es1))
 		priv->thermal_init = rcar_gen3_thermal_init_r8a7795es1;
 
-	spin_lock_init(&priv->lock);
-
 	platform_set_drvdata(pdev, priv);
 
 	/*
@@ -390,9 +364,9 @@ static int rcar_gen3_thermal_probe(struct platform_device *pdev)
 		if (!irqname)
 			return -ENOMEM;
 
-		ret = devm_request_threaded_irq(dev, irq, rcar_gen3_thermal_irq,
-						rcar_gen3_thermal_irq_thread,
-						IRQF_SHARED, irqname, priv);
+		ret = devm_request_threaded_irq(dev, irq, NULL,
+						rcar_gen3_thermal_irq,
+						IRQF_ONESHOT, irqname, priv);
 		if (ret)
 			return ret;
 	}
-- 
2.19.2