From b2bbc6a2ace78eaca2f6482b58b984519aa783ac Mon Sep 17 00:00:00 2001 From: Kuninori Morimoto Date: Thu, 31 Jan 2013 09:03:22 +0000 Subject: [PATCH] thermal: rcar: use mutex lock instead of spin lock Current R-Car thermal driver is using spin lock for each registers read/write, but it is pointless lock. This lock is required while reading temperature, but it needs long wait (= 300ms). So, this patch used mutex lock while reading temperature, instead of spin lock for each registers. Signed-off-by: Kuninori Morimoto Signed-off-by: Zhang Rui --- drivers/thermal/rcar_thermal.c | 30 +++++++----------------------- 1 file changed, 7 insertions(+), 23 deletions(-) diff --git a/drivers/thermal/rcar_thermal.c b/drivers/thermal/rcar_thermal.c index 068b2a1c5c15..e19b267f76d6 100644 --- a/drivers/thermal/rcar_thermal.c +++ b/drivers/thermal/rcar_thermal.c @@ -42,7 +42,7 @@ struct rcar_thermal_priv { void __iomem *base; struct device *dev; - spinlock_t lock; + struct mutex lock; }; #define MCELSIUS(temp) ((temp) * 1000) @@ -54,46 +54,26 @@ struct rcar_thermal_priv { */ static u32 rcar_thermal_read(struct rcar_thermal_priv *priv, u32 reg) { - unsigned long flags; - u32 ret; - - spin_lock_irqsave(&priv->lock, flags); - - ret = ioread32(priv->base + reg); - - spin_unlock_irqrestore(&priv->lock, flags); - - return ret; + return ioread32(priv->base + reg); } #if 0 /* no user at this point */ static void rcar_thermal_write(struct rcar_thermal_priv *priv, u32 reg, u32 data) { - unsigned long flags; - - spin_lock_irqsave(&priv->lock, flags); - iowrite32(data, priv->base + reg); - - spin_unlock_irqrestore(&priv->lock, flags); } #endif static void rcar_thermal_bset(struct rcar_thermal_priv *priv, u32 reg, u32 mask, u32 data) { - unsigned long flags; u32 val; - spin_lock_irqsave(&priv->lock, flags); - val = ioread32(priv->base + reg); val &= ~mask; val |= (data & mask); iowrite32(val, priv->base + reg); - - spin_unlock_irqrestore(&priv->lock, flags); } /* @@ -107,6 +87,8 @@ static int rcar_thermal_get_temp(struct thermal_zone_device *zone, int i; int ctemp, old, new; + mutex_lock(&priv->lock); + /* * TSC decides a value of CPTAP automatically, * and this is the conditions which validate interrupt. @@ -138,6 +120,8 @@ static int rcar_thermal_get_temp(struct thermal_zone_device *zone, *temp = MCELSIUS((ctemp * 5) - 65); + mutex_unlock(&priv->lock); + return 0; } @@ -225,7 +209,7 @@ static int rcar_thermal_probe(struct platform_device *pdev) } priv->dev = &pdev->dev; - spin_lock_init(&priv->lock); + mutex_init(&priv->lock); priv->base = devm_ioremap_nocache(&pdev->dev, res->start, resource_size(res)); if (!priv->base) { -- 2.34.1