USB: atm: cxacru: convert to use dev_groups

USB drivers now support the ability for the driver core to handle the
creation and removal of device-specific sysfs files in a race-free
manner.  Take advantage of that by converting the driver to use this by
moving the sysfs attributes into a group and assigning the dev_groups
pointer to it.

Link: https://lore.kernel.org/r/20190806144502.17792-4-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/atm/cxacru.c

@@ -539,6 +539,37 @@ CXACRU_SET_##_action(                                        adsl_config);
 
 CXACRU_ALL_FILES(INIT);
 
+static struct attribute *cxacru_attrs[] = {
+	&dev_attr_adsl_config.attr,
+	&dev_attr_adsl_state.attr,
+	&dev_attr_adsl_controller_version.attr,
+	&dev_attr_adsl_headend_environment.attr,
+	&dev_attr_adsl_headend.attr,
+	&dev_attr_modulation.attr,
+	&dev_attr_line_startable.attr,
+	&dev_attr_downstream_hec_errors.attr,
+	&dev_attr_upstream_hec_errors.attr,
+	&dev_attr_downstream_fec_errors.attr,
+	&dev_attr_upstream_fec_errors.attr,
+	&dev_attr_downstream_crc_errors.attr,
+	&dev_attr_upstream_crc_errors.attr,
+	&dev_attr_startup_attempts.attr,
+	&dev_attr_downstream_bits_per_frame.attr,
+	&dev_attr_upstream_bits_per_frame.attr,
+	&dev_attr_transmitter_power.attr,
+	&dev_attr_downstream_attenuation.attr,
+	&dev_attr_upstream_attenuation.attr,
+	&dev_attr_downstream_snr_margin.attr,
+	&dev_attr_upstream_snr_margin.attr,
+	&dev_attr_mac_address.attr,
+	&dev_attr_line_status.attr,
+	&dev_attr_link_status.attr,
+	&dev_attr_upstream_rate.attr,
+	&dev_attr_downstream_rate.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(cxacru);
+
 /* the following three functions are stolen from drivers/usb/core/message.c */
 static void cxacru_blocking_completion(struct urb *urb)
 {
@@ -736,17 +767,6 @@ static int cxacru_card_status(struct cxacru_data *instance)
 	return 0;
 }
 
-static void cxacru_remove_device_files(struct usbatm_data *usbatm_instance,
-		struct atm_dev *atm_dev)
-{
-	struct usb_interface *intf = usbatm_instance->usb_intf;
-
-	#define CXACRU_DEVICE_REMOVE_FILE(_name) \
-		device_remove_file(&intf->dev, &dev_attr_##_name);
-	CXACRU_ALL_FILES(REMOVE);
-	#undef CXACRU_DEVICE_REMOVE_FILE
-}
-
 static int cxacru_atm_start(struct usbatm_data *usbatm_instance,
 		struct atm_dev *atm_dev)
 {
@@ -765,13 +785,6 @@ static int cxacru_atm_start(struct usbatm_data *usbatm_instance,
 		return ret;
 	}
 
-	#define CXACRU_DEVICE_CREATE_FILE(_name) \
-		ret = device_create_file(&intf->dev, &dev_attr_##_name); \
-		if (unlikely(ret)) \
-			goto fail_sysfs;
-	CXACRU_ALL_FILES(CREATE);
-	#undef CXACRU_DEVICE_CREATE_FILE
-
 	/* start ADSL */
 	mutex_lock(&instance->adsl_state_serialize);
 	ret = cxacru_cm(instance, CM_REQUEST_CHIP_ADSL_LINE_START, NULL, 0, NULL, 0);
@@ -804,11 +817,6 @@ static int cxacru_atm_start(struct usbatm_data *usbatm_instance,
 	if (start_polling)
 		cxacru_poll_status(&instance->poll_work.work);
 	return 0;
-
-fail_sysfs:
-	usb_err(usbatm_instance, "cxacru_atm_start: device_create_file failed (%d)\n", ret);
-	cxacru_remove_device_files(usbatm_instance, atm_dev);
-	return ret;
 }
 
 static void cxacru_poll_status(struct work_struct *work)
@@ -1332,7 +1340,6 @@ static struct usbatm_driver cxacru_driver = {
 	.heavy_init	= cxacru_heavy_init,
 	.unbind		= cxacru_unbind,
 	.atm_start	= cxacru_atm_start,
-	.atm_stop	= cxacru_remove_device_files,
 	.bulk_in	= CXACRU_EP_DATA,
 	.bulk_out	= CXACRU_EP_DATA,
 	.rx_padding	= 3,
@@ -1364,7 +1371,8 @@ static struct usb_driver cxacru_usb_driver = {
 	.name		= cxacru_driver_name,
 	.probe		= cxacru_usb_probe,
 	.disconnect	= usbatm_usb_disconnect,
-	.id_table	= cxacru_usb_ids
+	.id_table	= cxacru_usb_ids,
+	.dev_groups	= cxacru_groups,
 };
 
 module_usb_driver(cxacru_usb_driver);