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| author | Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> | 2014-08-24 00:44:09 +0400 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2014-09-04 19:59:42 +0200 |
| commit | 91bfe2989af02e709ca01ccf518c4fbda3efc70f (patch) | |
| tree | a4ebc7cde4b09aaea773dba793062cee10fefe80 /drivers/i2c | |
| parent | 75b81f339c6af43f6f4a1b3eabe0603321dade65 (diff) | |
| download | linux-91bfe2989af02e709ca01ccf518c4fbda3efc70f.tar.gz | |
Revert "i2c: rcar: remove spinlock"
This reverts commit 150b8be3cda54412ad7b54f5392b513b25c0aaa7. 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>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-rcar.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index dc32f5fa75d0..1cc146cfc1f3 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -34,6 +34,7 @@ #include <linux/platform_device.h> #include <linux/pm_runtime.h> #include <linux/slab.h> +#include <linux/spinlock.h> /* register offsets */ #define ICSCR 0x00 /* slave ctrl */ @@ -95,6 +96,7 @@ struct rcar_i2c_priv { struct i2c_msg *msg; struct clk *clk; + spinlock_t lock; wait_queue_head_t wait; int pos; @@ -365,6 +367,9 @@ static irqreturn_t rcar_i2c_irq(int irq, void *ptr) struct rcar_i2c_priv *priv = ptr; u32 msr; + /*-------------- spin lock -----------------*/ + spin_lock(&priv->lock); + msr = rcar_i2c_read(priv, ICMSR); /* Only handle interrupts that are currently enabled */ @@ -403,6 +408,9 @@ out: wake_up(&priv->wait); } + spin_unlock(&priv->lock); + /*-------------- spin unlock -----------------*/ + return IRQ_HANDLED; } @@ -412,14 +420,21 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap, { struct rcar_i2c_priv *priv = i2c_get_adapdata(adap); struct device *dev = rcar_i2c_priv_to_dev(priv); + unsigned long flags; int i, ret, timeout; pm_runtime_get_sync(dev); + /*-------------- spin lock -----------------*/ + spin_lock_irqsave(&priv->lock, flags); + rcar_i2c_init(priv); /* start clock */ rcar_i2c_write(priv, ICCCR, priv->icccr); + spin_unlock_irqrestore(&priv->lock, flags); + /*-------------- spin unlock -----------------*/ + ret = rcar_i2c_bus_barrier(priv); if (ret < 0) goto out; @@ -431,6 +446,9 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap, break; } + /*-------------- spin lock -----------------*/ + spin_lock_irqsave(&priv->lock, flags); + /* init each data */ priv->msg = &msgs[i]; priv->pos = 0; @@ -440,6 +458,9 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap, ret = rcar_i2c_prepare_msg(priv); + spin_unlock_irqrestore(&priv->lock, flags); + /*-------------- spin unlock -----------------*/ + if (ret < 0) break; @@ -543,6 +564,7 @@ static int rcar_i2c_probe(struct platform_device *pdev) irq = platform_get_irq(pdev, 0); init_waitqueue_head(&priv->wait); + spin_lock_init(&priv->lock); adap = &priv->adap; adap->nr = pdev->id; |