i2c: stm32f7: perform I2C_ISR read once at beginning of event isr

Move readl_relaxed of I2C_ISR register at beginning of event isr
so that it done once for both master & slave handling.

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

Author: Alain Volmat

drivers/i2c/busses/i2c-stm32f7.c

@@ -1419,15 +1419,13 @@ static bool stm32f7_i2c_is_slave_busy(struct stm32f7_i2c_dev *i2c_dev)
 	return i == busy;
 }
 
-static irqreturn_t stm32f7_i2c_slave_isr_event(struct stm32f7_i2c_dev *i2c_dev)
+static irqreturn_t stm32f7_i2c_slave_isr_event(struct stm32f7_i2c_dev *i2c_dev, u32 status)
 {
 	void __iomem *base = i2c_dev->base;
-	u32 cr2, status, mask;
+	u32 cr2, mask;
 	u8 val;
 	int ret;
 
-	status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
-
 	/* Slave transmitter mode */
 	if (status & STM32F7_I2C_ISR_TXIS) {
 		i2c_slave_event(i2c_dev->slave_running,
@@ -1531,11 +1529,11 @@ static irqreturn_t stm32f7_i2c_isr_event_thread(int irq, void *data)
 	u32 status, mask;
 	int ret;
 
-	if (!i2c_dev->master_mode)
-		return stm32f7_i2c_slave_isr_event(i2c_dev);
-
 	status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
 
+	if (!i2c_dev->master_mode)
+		return stm32f7_i2c_slave_isr_event(i2c_dev, status);
+
 	/* NACK received */
 	if (status & STM32F7_I2C_ISR_NACKF) {
 		dev_dbg(i2c_dev->dev, "<%s>: Receive NACK (addr %x)\n",