i2c: iproc: handle only slave interrupts which are enabled

Handle only slave interrupts which are enabled.

The IS_OFFSET register contains the interrupt status bits which will be
set regardless of the enabling of the corresponding interrupt condition.
One must therefore look at both IS_OFFSET and IE_OFFSET to determine
whether an interrupt condition is set and enabled.

Fixes: c245d94 ("i2c: iproc: Add multi byte read-write support for slave mode")
Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>
Acked-by: Ray Jui <ray.jui@broadcom.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

drivers/i2c/busses/i2c-bcm-iproc.c

@@ -507,12 +507,17 @@ static void bcm_iproc_i2c_process_m_event(struct bcm_iproc_i2c_dev *iproc_i2c,
 static irqreturn_t bcm_iproc_i2c_isr(int irq, void *data)
 {
 	struct bcm_iproc_i2c_dev *iproc_i2c = data;
-	u32 status = iproc_i2c_rd_reg(iproc_i2c, IS_OFFSET);
+	u32 slave_status;
+	u32 status;
 	bool ret;
-	u32 sl_status = status & ISR_MASK_SLAVE;
 
-	if (sl_status) {
-		ret = bcm_iproc_i2c_slave_isr(iproc_i2c, sl_status);
+	status = iproc_i2c_rd_reg(iproc_i2c, IS_OFFSET);
+	/* process only slave interrupt which are enabled */
+	slave_status = status & iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET) &
+		       ISR_MASK_SLAVE;
+
+	if (slave_status) {
+		ret = bcm_iproc_i2c_slave_isr(iproc_i2c, slave_status);
 		if (ret)
 			return IRQ_HANDLED;
 		else