Revert "i2c: rcar: remove spinlock"
This reverts commit 150b8be3cd
.
The I2C core's per-adapter locks can't protect from IRQs, so the driver still
needs a spinlock to protect the register accesses.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: stable@vger.kernel.org # 3.16+
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
parent
75b81f339c
commit
91bfe2989a
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@ -34,6 +34,7 @@
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#include <linux/platform_device.h>
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#include <linux/platform_device.h>
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#include <linux/pm_runtime.h>
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#include <linux/pm_runtime.h>
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#include <linux/slab.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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/* register offsets */
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/* register offsets */
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#define ICSCR 0x00 /* slave ctrl */
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#define ICSCR 0x00 /* slave ctrl */
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@ -95,6 +96,7 @@ struct rcar_i2c_priv {
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struct i2c_msg *msg;
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struct i2c_msg *msg;
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struct clk *clk;
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struct clk *clk;
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spinlock_t lock;
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wait_queue_head_t wait;
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wait_queue_head_t wait;
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int pos;
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int pos;
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@ -365,6 +367,9 @@ static irqreturn_t rcar_i2c_irq(int irq, void *ptr)
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struct rcar_i2c_priv *priv = ptr;
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struct rcar_i2c_priv *priv = ptr;
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u32 msr;
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u32 msr;
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/*-------------- spin lock -----------------*/
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spin_lock(&priv->lock);
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msr = rcar_i2c_read(priv, ICMSR);
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msr = rcar_i2c_read(priv, ICMSR);
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/* Only handle interrupts that are currently enabled */
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/* Only handle interrupts that are currently enabled */
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@ -403,6 +408,9 @@ out:
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wake_up(&priv->wait);
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wake_up(&priv->wait);
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}
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}
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spin_unlock(&priv->lock);
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/*-------------- spin unlock -----------------*/
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return IRQ_HANDLED;
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return IRQ_HANDLED;
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}
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}
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@ -412,14 +420,21 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
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{
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{
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struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
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struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
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struct device *dev = rcar_i2c_priv_to_dev(priv);
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struct device *dev = rcar_i2c_priv_to_dev(priv);
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unsigned long flags;
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int i, ret, timeout;
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int i, ret, timeout;
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pm_runtime_get_sync(dev);
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pm_runtime_get_sync(dev);
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/*-------------- spin lock -----------------*/
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spin_lock_irqsave(&priv->lock, flags);
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rcar_i2c_init(priv);
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rcar_i2c_init(priv);
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/* start clock */
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/* start clock */
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rcar_i2c_write(priv, ICCCR, priv->icccr);
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rcar_i2c_write(priv, ICCCR, priv->icccr);
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spin_unlock_irqrestore(&priv->lock, flags);
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/*-------------- spin unlock -----------------*/
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ret = rcar_i2c_bus_barrier(priv);
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ret = rcar_i2c_bus_barrier(priv);
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if (ret < 0)
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if (ret < 0)
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goto out;
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goto out;
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@ -431,6 +446,9 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
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break;
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break;
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}
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}
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/*-------------- spin lock -----------------*/
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spin_lock_irqsave(&priv->lock, flags);
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/* init each data */
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/* init each data */
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priv->msg = &msgs[i];
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priv->msg = &msgs[i];
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priv->pos = 0;
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priv->pos = 0;
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@ -440,6 +458,9 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
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ret = rcar_i2c_prepare_msg(priv);
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ret = rcar_i2c_prepare_msg(priv);
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spin_unlock_irqrestore(&priv->lock, flags);
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/*-------------- spin unlock -----------------*/
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if (ret < 0)
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if (ret < 0)
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break;
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break;
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@ -543,6 +564,7 @@ static int rcar_i2c_probe(struct platform_device *pdev)
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irq = platform_get_irq(pdev, 0);
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irq = platform_get_irq(pdev, 0);
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init_waitqueue_head(&priv->wait);
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init_waitqueue_head(&priv->wait);
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spin_lock_init(&priv->lock);
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adap = &priv->adap;
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adap = &priv->adap;
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adap->nr = pdev->id;
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adap->nr = pdev->id;
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