i2c: rcar: check for no IRQ in rcar_i2c_irq()

Check if the ICMSR register (masked with the ICMIER register) evaluates to 0  in
the driver's interrupt handler and return IRQ_NONE in that case, like many other
drivers do.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

1 files changed, 7 insertions, 1 deletions

diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index c49b33e99d68..b694cba63807 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -363,6 +363,7 @@ static int rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr)
 static irqreturn_t rcar_i2c_irq(int irq, void *ptr)
 {
         struct rcar_i2c_priv *priv = ptr;
+        irqreturn_t result = IRQ_HANDLED;
         u32 msr;
 
         /*-------------- spin lock -----------------*/
@@ -372,6 +373,10 @@ static irqreturn_t rcar_i2c_irq(int irq, void *ptr)
 
         /* Only handle interrupts that are currently enabled */
         msr &= rcar_i2c_read(priv, ICMIER);
+        if (!msr) {
+                result = IRQ_NONE;
+                goto exit;
+        }
 
         /* Arbitration lost */
         if (msr & MAL) {
@@ -406,10 +411,11 @@ out:
                 wake_up(&priv->wait);
         }
 
+exit:
         spin_unlock(&priv->lock);
         /*-------------- spin unlock -----------------*/
 
-        return IRQ_HANDLED;
+        return result;
 }
 
 static int rcar_i2c_master_xfer(struct i2c_adapter *adap,