Sep 10 2012

usb: otg: move the dereference below the NULL test 

Author: Wei Yongjun <yongjun_wei@trendmicro.com.cn>

The dereference should be moved below the NULL test.

spatch with a semantic match is used to found this.
(http://coccinelle.lip6.fr/)

Signed-off-by: Wei Yongjun 
Signed-off-by: Felipe Balbi 

---
 drivers/usb/otg/fsl_otg.c | 34 ++++++++++++++++++++++++----------
 1 file changed, 24 insertions(+), 10 deletions(-)
 
diff --git a/drivers/usb/otg/fsl_otg.c b/drivers/usb/otg/fsl_otg.c
index 23c798c..c19d1d7 100644
--- a/drivers/usb/otg/fsl_otg.c
+++ b/drivers/usb/otg/fsl_otg.c
@@ -544,9 +544,13 @@ int fsl_otg_start_gadget(struct otg_fsm *fsm, int on)
  */
 static int fsl_otg_set_host(struct usb_otg *otg, struct usb_bus *host)
 {
-	struct fsl_otg *otg_dev = container_of(otg->phy, struct fsl_otg, phy);
+	struct fsl_otg *otg_dev;
+
+	if (!otg)
+		return -ENODEV;
 
-	if (!otg || otg_dev != fsl_otg_dev)
+	otg_dev = container_of(otg->phy, struct fsl_otg, phy);
+	if (otg_dev != fsl_otg_dev)
 		return -ENODEV;
 
 	otg->host = host;
@@ -590,12 +594,15 @@ static int fsl_otg_set_host(struct usb_otg *otg, struct usb_bus *host)
 static int fsl_otg_set_peripheral(struct usb_otg *otg,
 					struct usb_gadget *gadget)
 {
-	struct fsl_otg *otg_dev = container_of(otg->phy, struct fsl_otg, phy);
+	struct fsl_otg *otg_dev;
 
+	if (!otg)
+		return -ENODEV;
+
+	otg_dev = container_of(otg->phy, struct fsl_otg, phy);
 	VDBG("otg_dev 0x%x\n", (int)otg_dev);
 	VDBG("fsl_otg_dev 0x%x\n", (int)fsl_otg_dev);
-
-	if (!otg || otg_dev != fsl_otg_dev)
+	if (otg_dev != fsl_otg_dev)
 		return -ENODEV;
 
 	if (!gadget) {
@@ -660,10 +667,13 @@ static void fsl_otg_event(struct work_struct *work)
 /* B-device start SRP */
 static int fsl_otg_start_srp(struct usb_otg *otg)
 {
-	struct fsl_otg *otg_dev = container_of(otg->phy, struct fsl_otg, phy);
+	struct fsl_otg *otg_dev;
+
+	if (!otg || otg->phy->state != OTG_STATE_B_IDLE)
+		return -ENODEV;
 
-	if (!otg || otg_dev != fsl_otg_dev
-	    || otg->phy->state != OTG_STATE_B_IDLE)
+	otg_dev = container_of(otg->phy, struct fsl_otg, phy);
+	if (otg_dev != fsl_otg_dev)
 		return -ENODEV;
 
 	otg_dev->fsm.b_bus_req = 1;
@@ -675,9 +685,13 @@ static int fsl_otg_start_srp(struct usb_otg *otg)
 /* A_host suspend will call this function to start hnp */
 static int fsl_otg_start_hnp(struct usb_otg *otg)
 {
-	struct fsl_otg *otg_dev = container_of(otg->phy, struct fsl_otg, phy);
+	struct fsl_otg *otg_dev;
+
+	if (!otg)
+		return -ENODEV;
 
-	if (!otg || otg_dev != fsl_otg_dev)
+	otg_dev = container_of(otg->phy, struct fsl_otg, phy);
+	if (otg_dev != fsl_otg_dev)
 		return -ENODEV;
 
 	DBG("start_hnp...n");

qlambert