3 files changed, 44 insertions, 20 deletions

diff --git a/drivers/usb/atm/cxacru.c b/drivers/usb/atm/cxacru.c
index 8da4a06bf140..4bead3da3850 100644
--- a/drivers/usb/atm/cxacru.c
+++ b/drivers/usb/atm/cxacru.c
@@ -200,9 +200,12 @@ static DEVICE_ATTR(_name, S_IWUSR | S_IRUGO, \
 static ssize_t cxacru_sysfs_show_##_name(struct device *dev, \
         struct device_attribute *attr, char *buf) \
 { \
-        struct usb_interface *intf = to_usb_interface(dev); \
-        struct usbatm_data *usbatm_instance = usb_get_intfdata(intf); \
-        struct cxacru_data *instance = usbatm_instance->driver_data; \
+        struct cxacru_data *instance = to_usbatm_driver_data(\
+                to_usb_interface(dev)); \
+\
+        if (instance == NULL) \
+                return -ENODEV; \
+\
         return cxacru_sysfs_showattr_##_type(instance->card_info[_value], buf); \
 } \
 CXACRU__ATTR_INIT(_name)
@@ -288,22 +291,28 @@ static ssize_t cxacru_sysfs_showattr_MODU(u32 value, char *buf)
 static ssize_t cxacru_sysfs_show_mac_address(struct device *dev,
         struct device_attribute *attr, char *buf)
 {
-        struct usb_interface *intf = to_usb_interface(dev);
-        struct usbatm_data *usbatm_instance = usb_get_intfdata(intf);
-        struct atm_dev *atm_dev = usbatm_instance->atm_dev;
+        struct cxacru_data *instance = to_usbatm_driver_data(
+                        to_usb_interface(dev));
 
-        return snprintf(buf, PAGE_SIZE, "%pM\n", atm_dev->esi);
+        if (instance == NULL || instance->usbatm->atm_dev == NULL)
+                return -ENODEV;
+
+        return snprintf(buf, PAGE_SIZE, "%pM\n",
+                instance->usbatm->atm_dev->esi);
 }
 
 static ssize_t cxacru_sysfs_show_adsl_state(struct device *dev,
         struct device_attribute *attr, char *buf)
 {
-        struct usb_interface *intf = to_usb_interface(dev);
-        struct usbatm_data *usbatm_instance = usb_get_intfdata(intf);
-        struct cxacru_data *instance = usbatm_instance->driver_data;
-        u32 value = instance->card_info[CXINF_LINE_STARTABLE];
-
         static char *str[] = { "running", "stopped" };
+        struct cxacru_data *instance = to_usbatm_driver_data(
+                        to_usb_interface(dev));
+        u32 value;
+
+        if (instance == NULL)
+                return -ENODEV;
+
+        value = instance->card_info[CXINF_LINE_STARTABLE];
         if (unlikely(value >= ARRAY_SIZE(str)))
                 return snprintf(buf, PAGE_SIZE, "%u\n", value);
         return snprintf(buf, PAGE_SIZE, "%s\n", str[value]);
@@ -312,9 +321,8 @@ static ssize_t cxacru_sysfs_show_adsl_state(struct device *dev,
 static ssize_t cxacru_sysfs_store_adsl_state(struct device *dev,
         struct device_attribute *attr, const char *buf, size_t count)
 {
-        struct usb_interface *intf = to_usb_interface(dev);
-        struct usbatm_data *usbatm_instance = usb_get_intfdata(intf);
-        struct cxacru_data *instance = usbatm_instance->driver_data;
+        struct cxacru_data *instance = to_usbatm_driver_data(
+                        to_usb_interface(dev));
         int ret;
         int poll = -1;
         char str_cmd[8];
@@ -328,13 +336,16 @@ static ssize_t cxacru_sysfs_store_adsl_state(struct device *dev,
                 return -EINVAL;
         ret = 0;
 
+        if (instance == NULL)
+                return -ENODEV;
+
         if (mutex_lock_interruptible(&instance->adsl_state_serialize))
                 return -ERESTARTSYS;
 
         if (!strcmp(str_cmd, "stop") || !strcmp(str_cmd, "restart")) {
                 ret = cxacru_cm(instance, CM_REQUEST_CHIP_ADSL_LINE_STOP, NULL, 0, NULL, 0);
                 if (ret < 0) {
-                        atm_err(usbatm_instance, "change adsl state:"
+                        atm_err(instance->usbatm, "change adsl state:"
                                 " CHIP_ADSL_LINE_STOP returned %d\n", ret);
 
                         ret = -EIO;
@@ -354,7 +365,7 @@ static ssize_t cxacru_sysfs_store_adsl_state(struct device *dev,
         if (!strcmp(str_cmd, "start") || !strcmp(str_cmd, "restart")) {
                 ret = cxacru_cm(instance, CM_REQUEST_CHIP_ADSL_LINE_START, NULL, 0, NULL, 0);
                 if (ret < 0) {
-                        atm_err(usbatm_instance, "change adsl state:"
+                        atm_err(instance->usbatm, "change adsl state:"
                                 " CHIP_ADSL_LINE_START returned %d\n", ret);
 
                         ret = -EIO;
@@ -649,9 +660,6 @@ static int cxacru_atm_start(struct usbatm_data *usbatm_instance,
 {
         struct cxacru_data *instance = usbatm_instance->driver_data;
         struct usb_interface *intf = usbatm_instance->usb_intf;
-        /*
-        struct atm_dev *atm_dev = usbatm_instance->atm_dev;
-        */
         int ret;
         int start_polling = 1;
 
diff --git a/drivers/usb/atm/usbatm.c b/drivers/usb/atm/usbatm.c
index fbea8563df1e..40380434ba96 100644
--- a/drivers/usb/atm/usbatm.c
+++ b/drivers/usb/atm/usbatm.c
@@ -1333,6 +1333,7 @@ void usbatm_usb_disconnect(struct usb_interface *intf)
         if (instance->atm_dev) {
                 sysfs_remove_link(&instance->atm_dev->class_dev.kobj, "device");
                 atm_dev_deregister(instance->atm_dev);
+                instance->atm_dev = NULL;
         }
 
         usbatm_put_instance(instance);  /* taken in usbatm_usb_probe */
diff --git a/drivers/usb/atm/usbatm.h b/drivers/usb/atm/usbatm.h
index f6f4508a9d42..0863f85fcc26 100644
--- a/drivers/usb/atm/usbatm.h
+++ b/drivers/usb/atm/usbatm.h
@@ -204,4 +204,19 @@ struct usbatm_data {
         struct urb *urbs[0];
 };
 
+static inline void *to_usbatm_driver_data(struct usb_interface *intf)
+{
+        struct usbatm_data *usbatm_instance;
+
+        if (intf == NULL)
+                return NULL;
+
+        usbatm_instance = usb_get_intfdata(intf);
+
+        if (usbatm_instance == NULL) /* set NULL before unbind() */
+                return NULL;
+
+        return usbatm_instance->driver_data; /* set NULL after unbind() */
+}
+
 #endif  /* _USBATM_H_ */