4 files changed, 61 insertions, 20 deletions

diff --git a/drivers/usb/gadget/legacy/Kconfig b/drivers/usb/gadget/legacy/Kconfig
index 69ff7f8c86f5..119a4e47681f 100644
--- a/drivers/usb/gadget/legacy/Kconfig
+++ b/drivers/usb/gadget/legacy/Kconfig
@@ -149,21 +149,21 @@ config USB_ETH_RNDIS
 	   is given in comments found in that info file.
 
 config USB_ETH_EEM
-       bool "Ethernet Emulation Model (EEM) support"
-       depends on USB_ETH
+	bool "Ethernet Emulation Model (EEM) support"
+	depends on USB_ETH
 	select USB_LIBCOMPOSITE
 	select USB_F_EEM
-       help
-         CDC EEM is a newer USB standard that is somewhat simpler than CDC ECM
-         and therefore can be supported by more hardware.  Technically ECM and
-         EEM are designed for different applications.  The ECM model extends
-         the network interface to the target (e.g. a USB cable modem), and the
-         EEM model is for mobile devices to communicate with hosts using
-         ethernet over USB.  For Linux gadgets, however, the interface with
-         the host is the same (a usbX device), so the differences are minimal.
-
-         If you say "y" here, the Ethernet gadget driver will use the EEM
-         protocol rather than ECM.  If unsure, say "n".
+	help
+	  CDC EEM is a newer USB standard that is somewhat simpler than CDC ECM
+	  and therefore can be supported by more hardware.  Technically ECM and
+	  EEM are designed for different applications.  The ECM model extends
+	  the network interface to the target (e.g. a USB cable modem), and the
+	  EEM model is for mobile devices to communicate with hosts using
+	  ethernet over USB.  For Linux gadgets, however, the interface with
+	  the host is the same (a usbX device), so the differences are minimal.
+
+	  If you say "y" here, the Ethernet gadget driver will use the EEM
+	  protocol rather than ECM.  If unsure, say "n".
 
 config USB_G_NCM
 	tristate "Network Control Model (NCM) support"
diff --git a/drivers/usb/gadget/legacy/acm_ms.c b/drivers/usb/gadget/legacy/acm_ms.c
index af16672d5118..59be2d8417c9 100644
--- a/drivers/usb/gadget/legacy/acm_ms.c
+++ b/drivers/usb/gadget/legacy/acm_ms.c
@@ -105,7 +105,6 @@ static struct usb_function *f_msg;
  */
 static int acm_ms_do_config(struct usb_configuration *c)
 {
-	struct fsg_opts *opts;
 	int	status;
 
 	if (gadget_is_otg(c->cdev->gadget)) {
@@ -113,8 +112,6 @@ static int acm_ms_do_config(struct usb_configuration *c)
 		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 	}
 
-	opts = fsg_opts_from_func_inst(fi_msg);
-
 	f_acm = usb_get_function(f_acm_inst);
 	if (IS_ERR(f_acm))
 		return PTR_ERR(f_acm);
diff --git a/drivers/usb/gadget/legacy/mass_storage.c b/drivers/usb/gadget/legacy/mass_storage.c
index fd5595ac5bf7..f18f77584fc2 100644
--- a/drivers/usb/gadget/legacy/mass_storage.c
+++ b/drivers/usb/gadget/legacy/mass_storage.c
@@ -105,7 +105,6 @@ FSG_MODULE_PARAMETERS(/* no prefix */, mod_data);
 
 static int msg_do_config(struct usb_configuration *c)
 {
-	struct fsg_opts *opts;
 	int ret;
 
 	if (gadget_is_otg(c->cdev->gadget)) {
@@ -113,8 +112,6 @@ static int msg_do_config(struct usb_configuration *c)
 		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 	}
 
-	opts = fsg_opts_from_func_inst(fi_msg);
-
 	f_msg = usb_get_function(fi_msg);
 	if (IS_ERR(f_msg))
 		return PTR_ERR(f_msg);
diff --git a/drivers/usb/gadget/legacy/serial.c b/drivers/usb/gadget/legacy/serial.c
index de30d7628eef..da44f89f5e73 100644
--- a/drivers/usb/gadget/legacy/serial.c
+++ b/drivers/usb/gadget/legacy/serial.c
@@ -97,6 +97,36 @@ static unsigned n_ports = 1;
 module_param(n_ports, uint, 0);
 MODULE_PARM_DESC(n_ports, "number of ports to create, default=1");
 
+static bool enable = true;
+
+static int switch_gserial_enable(bool do_enable);
+
+static int enable_set(const char *s, const struct kernel_param *kp)
+{
+	bool do_enable;
+	int ret;
+
+	if (!s)	/* called for no-arg enable == default */
+		return 0;
+
+	ret = strtobool(s, &do_enable);
+	if (ret || enable == do_enable)
+		return ret;
+
+	ret = switch_gserial_enable(do_enable);
+	if (!ret)
+		enable = do_enable;
+
+	return ret;
+}
+
+static const struct kernel_param_ops enable_ops = {
+	.set = enable_set,
+	.get = param_get_bool,
+};
+
+module_param_cb(enable, &enable_ops, &enable, 0644);
+
 /*-------------------------------------------------------------------------*/
 
 static struct usb_configuration serial_config_driver = {
@@ -240,6 +270,19 @@ static struct usb_composite_driver gserial_driver = {
 	.unbind		= gs_unbind,
 };
 
+static int switch_gserial_enable(bool do_enable)
+{
+	if (!serial_config_driver.label)
+		/* init() was not called, yet */
+		return 0;
+
+	if (do_enable)
+		return usb_composite_probe(&gserial_driver);
+
+	usb_composite_unregister(&gserial_driver);
+	return 0;
+}
+
 static int __init init(void)
 {
 	/* We *could* export two configs; that'd be much cleaner...
@@ -266,12 +309,16 @@ static int __init init(void)
 	}
 	strings_dev[STRING_DESCRIPTION_IDX].s = serial_config_driver.label;
 
+	if (!enable)
+		return 0;
+
 	return usb_composite_probe(&gserial_driver);
 }
 module_init(init);
 
 static void __exit cleanup(void)
 {
-	usb_composite_unregister(&gserial_driver);
+	if (enable)
+		usb_composite_unregister(&gserial_driver);
 }
 module_exit(cleanup);