[PATCH] i2c: fix crash with msgs is NULL points

[wangyouwan]

From: youwan Wang <wangyouwan@xxxxxxx>

There is some probability that msgs is empty

Signed-off-by: youwan Wang <wangyouwan@xxxxxxx>
---
 drivers/i2c/busses/i2c-designware-master.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
index 55ea91a63382..e11a73fd0a41 100644
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -366,12 +366,17 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
 	struct i2c_msg *msgs = dev->msgs;
 	u32 intr_mask;
 	int tx_limit, rx_limit;
-	u32 addr = msgs[dev->msg_write_idx].addr;
+	u32 addr;
 	u32 buf_len = dev->tx_buf_len;
 	u8 *buf = dev->tx_buf;
 	bool need_restart = false;
 	unsigned int flr;
 
+	if (WARN_ON(!msgs))
+		return;
+
+	addr = msgs[dev->msg_write_idx].addr;
+
 	intr_mask = DW_IC_INTR_MASTER_MASK;
 
 	for (; dev->msg_write_idx < dev->msgs_num; dev->msg_write_idx++) {
-- 
2.25.1