[PATCH v4 1/2] thermal: rcar_gen3_thermal: fix interrupt type

[Jiada Wang]

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_w...@mentor.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