[PATCH v2 1/3] i2c: xiic: Add timeout to the rx fifo wait loop

[shubhrajyoti.datta@xxxxxxxxx]

From: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>

Add timeout to the rx fifo empty wait loop. Also check for the return
value for xiic_reinit and pass it to xiic_start_xfer.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>
Signed-off-by: Michal Simek <michal.simek@xxxxxxxxxx>
---
 drivers/i2c/busses/i2c-xiic.c | 52 ++++++++++++++++++++++++++++++++++---------
 1 file changed, 42 insertions(+), 10 deletions(-)

diff --git a/drivers/i2c/busses/i2c-xiic.c b/drivers/i2c/busses/i2c-xiic.c
index f42930c..700b401 100644
--- a/drivers/i2c/busses/i2c-xiic.c
+++ b/drivers/i2c/busses/i2c-xiic.c
@@ -156,6 +156,8 @@ struct xiic_i2c {
 #define XIIC_RESET_MASK             0xAUL
 
 #define XIIC_PM_TIMEOUT		1000	/* ms */
+/* timeout waiting for the controller to respond */
+#define XIIC_I2C_TIMEOUT	(msecs_to_jiffies(1000))
 /*
  * The following constant is used for the device global interrupt enable
  * register, to enable all interrupts for the device, this is the only bit
@@ -166,7 +168,7 @@ struct xiic_i2c {
 #define xiic_tx_space(i2c) ((i2c)->tx_msg->len - (i2c)->tx_pos)
 #define xiic_rx_space(i2c) ((i2c)->rx_msg->len - (i2c)->rx_pos)
 
-static void xiic_start_xfer(struct xiic_i2c *i2c);
+static int xiic_start_xfer(struct xiic_i2c *i2c);
 static void __xiic_start_xfer(struct xiic_i2c *i2c);
 
 /*
@@ -247,17 +249,29 @@ static inline void xiic_irq_clr_en(struct xiic_i2c *i2c, u32 mask)
 	xiic_irq_en(i2c, mask);
 }
 
-static void xiic_clear_rx_fifo(struct xiic_i2c *i2c)
+static int xiic_clear_rx_fifo(struct xiic_i2c *i2c)
 {
 	u8 sr;
+	unsigned long timeout;
+
+	timeout = jiffies + XIIC_I2C_TIMEOUT;
 	for (sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET);
 		!(sr & XIIC_SR_RX_FIFO_EMPTY_MASK);
-		sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET))
+		sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET)) {
 		xiic_getreg8(i2c, XIIC_DRR_REG_OFFSET);
+		if (time_after(jiffies, timeout)) {
+			dev_err(i2c->dev, "Failed to clear rx fifo\n");
+				return -ETIMEDOUT;
+		}
+	}
+
+	return 0;
 }
 
-static void xiic_reinit(struct xiic_i2c *i2c)
+static int xiic_reinit(struct xiic_i2c *i2c)
 {
+	int ret;
+
 	xiic_setreg32(i2c, XIIC_RESETR_OFFSET, XIIC_RESET_MASK);
 
 	/* Set receive Fifo depth to maximum (zero based). */
@@ -270,12 +284,16 @@ static void xiic_reinit(struct xiic_i2c *i2c)
 	xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, XIIC_CR_ENABLE_DEVICE_MASK);
 
 	/* make sure RX fifo is empty */
-	xiic_clear_rx_fifo(i2c);
+	ret = xiic_clear_rx_fifo(i2c);
+	if (ret)
+		return ret;
 
 	/* Enable interrupts */
 	xiic_setreg32(i2c, XIIC_DGIER_OFFSET, XIIC_GINTR_ENABLE_MASK);
 
 	xiic_irq_clr_en(i2c, XIIC_INTR_ARB_LOST_MASK);
+
+	return 0;
 }
 
 static void xiic_deinit(struct xiic_i2c *i2c)
@@ -655,12 +673,18 @@ static void __xiic_start_xfer(struct xiic_i2c *i2c)
 
 }
 
-static void xiic_start_xfer(struct xiic_i2c *i2c)
+static int xiic_start_xfer(struct xiic_i2c *i2c)
 {
+	int ret;
 	mutex_lock(&i2c->lock);
-	xiic_reinit(i2c);
-	__xiic_start_xfer(i2c);
+
+	ret = xiic_reinit(i2c);
+	if (!ret)
+		__xiic_start_xfer(i2c);
+
 	mutex_unlock(&i2c->lock);
+
+	return ret;
 }
 
 static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
@@ -682,7 +706,11 @@ static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 	i2c->tx_msg = msgs;
 	i2c->nmsgs = num;
 
-	xiic_start_xfer(i2c);
+	err = xiic_start_xfer(i2c);
+	if (err < 0) {
+		dev_err(adap->dev.parent, "Error xiic_start_xfer\n");
+		goto out;
+	}
 
 	if (wait_event_timeout(i2c->wait, (i2c->state == STATE_ERROR) ||
 		(i2c->state == STATE_DONE), HZ)) {
@@ -794,7 +822,11 @@ static int xiic_i2c_probe(struct platform_device *pdev)
 	if (!(sr & XIIC_SR_TX_FIFO_EMPTY_MASK))
 		i2c->endianness = BIG;
 
-	xiic_reinit(i2c);
+	ret = xiic_reinit(i2c);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Cannot xiic_reinit\n");
+		goto err_clk_dis;
+	}
 
 	/* add i2c adapter to i2c tree */
 	ret = i2c_add_adapter(&i2c->adap);
-- 
2.1.1