From c7f82ea8605627b3088f166d9f4a5ca7857e8383 Mon Sep 17 00:00:00 2001
From: Colin Ian King <colin.king@canonical.com>
Date: Mon, 20 Mar 2017 11:51:23 +0000
Subject: [PATCH] i2c: designware-baytrail: fix potential null pointer dereference on dev
Git-commit: c7f82ea8605627b3088f166d9f4a5ca7857e8383
Patch-mainline: 4.12-rc1
References: bsc#1011913

The assignment to addr requires a call to get_sem_addr that dereferences
dev, however, this dereference occurs before a null pointer check on dev.
Move this assignment after the null check on dev to avoid a potential null
pointer dereference.

Detected by CoverityScan, CID#1419700 ("Dereference before null check")

Fixes: fd476fa22a1f432 ("i2c: designware-baytrail: Add support for cherrytrail")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/i2c/busses/i2c-designware-baytrail.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/i2c/busses/i2c-designware-baytrail.c
+++ b/drivers/i2c/busses/i2c-designware-baytrail.c
@@ -71,7 +71,7 @@ static void reset_semaphore(struct dw_i2
 
 static int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
 {
-	u32 addr = get_sem_addr(dev);
+	u32 addr;
 	u32 sem = PUNIT_SEMAPHORE_ACQUIRE;
 	int ret;
 	unsigned long start, end;
@@ -95,6 +95,8 @@ static int baytrail_i2c_acquire(struct d
 	 */
 	pm_qos_update_request(&dev->pm_qos, 0);
 
+	addr = get_sem_addr(dev);
+
 	/* host driver writes to side band semaphore register */
 	ret = iosf_mbi_write(BT_MBI_UNIT_PMC, BT_MBI_BUNIT_WRITE, addr, sem);
 	if (ret) {
