diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index 3c80bfbf3bec..66a6ac50a4cd 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -400,6 +400,7 @@ struct cp210x_special_chars {
 };
 
 /* CP210X_VENDOR_SPECIFIC values */
+#define CP210X_GET_FW_VER	0x000E
 #define CP210X_READ_2NCONFIG	0x000E
 #define CP210X_GET_FW_VER_2N	0x0010
 #define CP210X_READ_LATCH	0x00C2
@@ -638,7 +639,7 @@ static int cp210x_read_reg_block(struct usb_serial_port *port, u8 req,
 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
 			req, REQTYPE_INTERFACE_TO_HOST, 0,
 			port_priv->bInterfaceNumber, dmabuf, bufsize,
-			USB_CTRL_SET_TIMEOUT);
+			USB_CTRL_GET_TIMEOUT);
 	if (result == bufsize) {
 		memcpy(buf, dmabuf, bufsize);
 		result = 0;
@@ -1145,33 +1146,6 @@ static void cp210x_disable_event_mode(struct usb_serial_port *port)
 	port_priv->event_mode = false;
 }
 
-static int cp210x_set_chars(struct usb_serial_port *port,
-		struct cp210x_special_chars *chars)
-{
-	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
-	struct usb_serial *serial = port->serial;
-	void *dmabuf;
-	int result;
-
-	dmabuf = kmemdup(chars, sizeof(*chars), GFP_KERNEL);
-	if (!dmabuf)
-		return -ENOMEM;
-
-	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
-				CP210X_SET_CHARS, REQTYPE_HOST_TO_INTERFACE, 0,
-				port_priv->bInterfaceNumber,
-				dmabuf, sizeof(*chars), USB_CTRL_SET_TIMEOUT);
-
-	kfree(dmabuf);
-
-	if (result < 0) {
-		dev_err(&port->dev, "failed to set special chars: %d\n", result);
-		return result;
-	}
-
-	return 0;
-}
-
 static bool cp210x_termios_change(const struct ktermios *a, const struct ktermios *b)
 {
 	bool iflag_change, cc_change;
@@ -1192,6 +1166,7 @@ static void cp210x_set_flow_control(struct tty_struct *tty,
 	struct cp210x_flow_ctl flow_ctl;
 	u32 flow_repl;
 	u32 ctl_hs;
+	bool crtscts;
 	int ret;
 
 	/*
@@ -1218,9 +1193,12 @@ static void cp210x_set_flow_control(struct tty_struct *tty,
 		chars.bXonChar = START_CHAR(tty);
 		chars.bXoffChar = STOP_CHAR(tty);
 
-		ret = cp210x_set_chars(port, &chars);
-		if (ret)
-			return;
+		ret = cp210x_write_reg_block(port, CP210X_SET_CHARS, &chars,
+				sizeof(chars));
+		if (ret) {
+			dev_err(&port->dev, "failed to set special chars: %d\n",
+					ret);
+		}
 	}
 
 	mutex_lock(&port_priv->mutex);
@@ -1249,14 +1227,14 @@ static void cp210x_set_flow_control(struct tty_struct *tty,
 			flow_repl |= CP210X_SERIAL_RTS_FLOW_CTL;
 		else
 			flow_repl |= CP210X_SERIAL_RTS_INACTIVE;
-		port_priv->crtscts = true;
+		crtscts = true;
 	} else {
 		ctl_hs &= ~CP210X_SERIAL_CTS_HANDSHAKE;
 		if (port_priv->rts)
 			flow_repl |= CP210X_SERIAL_RTS_ACTIVE;
 		else
 			flow_repl |= CP210X_SERIAL_RTS_INACTIVE;
-		port_priv->crtscts = false;
+		crtscts = false;
 	}
 
 	if (I_IXOFF(tty)) {
@@ -1279,8 +1257,12 @@ static void cp210x_set_flow_control(struct tty_struct *tty,
 	flow_ctl.ulControlHandshake = cpu_to_le32(ctl_hs);
 	flow_ctl.ulFlowReplace = cpu_to_le32(flow_repl);
 
-	cp210x_write_reg_block(port, CP210X_SET_FLOW, &flow_ctl,
+	ret = cp210x_write_reg_block(port, CP210X_SET_FLOW, &flow_ctl,
 			sizeof(flow_ctl));
+	if (ret)
+		goto out_unlock;
+
+	port_priv->crtscts = crtscts;
 out_unlock:
 	mutex_unlock(&port_priv->mutex);
 }
@@ -2111,12 +2093,26 @@ static int cp210x_get_fw_version(struct usb_serial *serial, u16 value)
 	return 0;
 }
 
-static void cp210x_determine_quirks(struct usb_serial *serial)
+static void cp210x_determine_type(struct usb_serial *serial)
 {
 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
 	int ret;
 
+	ret = cp210x_read_vendor_block(serial, REQTYPE_DEVICE_TO_HOST,
+			CP210X_GET_PARTNUM, &priv->partnum,
+			sizeof(priv->partnum));
+	if (ret < 0) {
+		dev_warn(&serial->interface->dev,
+				"querying part number failed\n");
+		priv->partnum = CP210X_PARTNUM_UNKNOWN;
+		return;
+	}
+
 	switch (priv->partnum) {
+	case CP210X_PARTNUM_CP2105:
+	case CP210X_PARTNUM_CP2108:
+		cp210x_get_fw_version(serial, CP210X_GET_FW_VER);
+		break;
 	case CP210X_PARTNUM_CP2102N_QFN28:
 	case CP210X_PARTNUM_CP2102N_QFN24:
 	case CP210X_PARTNUM_CP2102N_QFN20:
@@ -2140,18 +2136,9 @@ static int cp210x_attach(struct usb_serial *serial)
 	if (!priv)
 		return -ENOMEM;
 
-	result = cp210x_read_vendor_block(serial, REQTYPE_DEVICE_TO_HOST,
-					  CP210X_GET_PARTNUM, &priv->partnum,
-					  sizeof(priv->partnum));
-	if (result < 0) {
-		dev_warn(&serial->interface->dev,
-			 "querying part number failed\n");
-		priv->partnum = CP210X_PARTNUM_UNKNOWN;
-	}
-
 	usb_set_serial_data(serial, priv);
 
-	cp210x_determine_quirks(serial);
+	cp210x_determine_type(serial);
 	cp210x_init_max_speed(serial);
 
 	result = cp210x_gpio_init(serial);
diff --git a/drivers/usb/serial/cypress_m8.c b/drivers/usb/serial/cypress_m8.c
index 6b18990258c3..6924fa95f6bd 100644
--- a/drivers/usb/serial/cypress_m8.c
+++ b/drivers/usb/serial/cypress_m8.c
@@ -1199,9 +1199,9 @@ MODULE_AUTHOR(DRIVER_AUTHOR);
 MODULE_DESCRIPTION(DRIVER_DESC);
 MODULE_LICENSE("GPL");
 
-module_param(stats, bool, S_IRUGO | S_IWUSR);
+module_param(stats, bool, 0644);
 MODULE_PARM_DESC(stats, "Enable statistics or not");
-module_param(interval, int, S_IRUGO | S_IWUSR);
+module_param(interval, int, 0644);
 MODULE_PARM_DESC(interval, "Overrides interrupt interval");
-module_param(unstable_bauds, bool, S_IRUGO | S_IWUSR);
+module_param(unstable_bauds, bool, 0644);
 MODULE_PARM_DESC(unstable_bauds, "Allow unstable baud rates");
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 33bbb3470ca3..99d19828dae6 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -2938,5 +2938,5 @@ MODULE_AUTHOR(DRIVER_AUTHOR);
 MODULE_DESCRIPTION(DRIVER_DESC);
 MODULE_LICENSE("GPL");
 
-module_param(ndi_latency_timer, int, S_IRUGO | S_IWUSR);
+module_param(ndi_latency_timer, int, 0644);
 MODULE_PARM_DESC(ndi_latency_timer, "NDI device latency timer override");
diff --git a/drivers/usb/serial/garmin_gps.c b/drivers/usb/serial/garmin_gps.c
index 756d1ac7e96f..e5c75944ebb7 100644
--- a/drivers/usb/serial/garmin_gps.c
+++ b/drivers/usb/serial/garmin_gps.c
@@ -1444,5 +1444,5 @@ MODULE_AUTHOR(DRIVER_AUTHOR);
 MODULE_DESCRIPTION(DRIVER_DESC);
 MODULE_LICENSE("GPL");
 
-module_param(initial_mode, int, S_IRUGO);
+module_param(initial_mode, int, 0444);
 MODULE_PARM_DESC(initial_mode, "Initial mode");
diff --git a/drivers/usb/serial/io_edgeport.c b/drivers/usb/serial/io_edgeport.c
index ea4edf5eed27..bdee78cc4a07 100644
--- a/drivers/usb/serial/io_edgeport.c
+++ b/drivers/usb/serial/io_edgeport.c
@@ -389,39 +389,6 @@ static void update_edgeport_E2PROM(struct edgeport_serial *edge_serial)
 	release_firmware(fw);
 }
 
-#if 0
-/************************************************************************
- *
- *  Get string descriptor from device
- *
- ************************************************************************/
-static int get_string_desc(struct usb_device *dev, int Id,
-				struct usb_string_descriptor **pRetDesc)
-{
-	struct usb_string_descriptor StringDesc;
-	struct usb_string_descriptor *pStringDesc;
-
-	dev_dbg(&dev->dev, "%s - USB String ID = %d\n", __func__, Id);
-
-	if (!usb_get_descriptor(dev, USB_DT_STRING, Id, &StringDesc,
-						sizeof(StringDesc)))
-		return 0;
-
-	pStringDesc = kmalloc(StringDesc.bLength, GFP_KERNEL);
-	if (!pStringDesc)
-		return -1;
-
-	if (!usb_get_descriptor(dev, USB_DT_STRING, Id, pStringDesc,
-							StringDesc.bLength)) {
-		kfree(pStringDesc);
-		return -1;
-	}
-
-	*pRetDesc = pStringDesc;
-	return 0;
-}
-#endif
-
 static void dump_product_info(struct edgeport_serial *edge_serial,
 			      struct edgeport_product_info *product_info)
 {
diff --git a/drivers/usb/serial/io_ti.c b/drivers/usb/serial/io_ti.c
index 84b848d2794e..a7b3c15957ba 100644
--- a/drivers/usb/serial/io_ti.c
+++ b/drivers/usb/serial/io_ti.c
@@ -2746,9 +2746,9 @@ MODULE_DESCRIPTION(DRIVER_DESC);
 MODULE_LICENSE("GPL");
 MODULE_FIRMWARE("edgeport/down3.bin");
 
-module_param(ignore_cpu_rev, bool, S_IRUGO | S_IWUSR);
+module_param(ignore_cpu_rev, bool, 0644);
 MODULE_PARM_DESC(ignore_cpu_rev,
 			"Ignore the cpu revision when connecting to a device");
 
-module_param(default_uart_mode, int, S_IRUGO | S_IWUSR);
+module_param(default_uart_mode, int, 0644);
 MODULE_PARM_DESC(default_uart_mode, "Default uart_mode, 0=RS232, ...");
diff --git a/drivers/usb/serial/ipaq.c b/drivers/usb/serial/ipaq.c
index f81746c3c26c..e11441bac44f 100644
--- a/drivers/usb/serial/ipaq.c
+++ b/drivers/usb/serial/ipaq.c
@@ -599,10 +599,10 @@ MODULE_AUTHOR(DRIVER_AUTHOR);
 MODULE_DESCRIPTION(DRIVER_DESC);
 MODULE_LICENSE("GPL");
 
-module_param(connect_retries, int, S_IRUGO|S_IWUSR);
+module_param(connect_retries, int, 0644);
 MODULE_PARM_DESC(connect_retries,
 		"Maximum number of connect retries (one second each)");
 
-module_param(initial_wait, int, S_IRUGO|S_IWUSR);
+module_param(initial_wait, int, 0644);
 MODULE_PARM_DESC(initial_wait,
 		"Time to wait before attempting a connection (in seconds)");
diff --git a/drivers/usb/serial/iuu_phoenix.c b/drivers/usb/serial/iuu_phoenix.c
index 19753611e7b0..0be3b5e1eaf3 100644
--- a/drivers/usb/serial/iuu_phoenix.c
+++ b/drivers/usb/serial/iuu_phoenix.c
@@ -1188,20 +1188,20 @@ MODULE_AUTHOR("Alain Degreffe eczema@ecze.com");
 MODULE_DESCRIPTION(DRIVER_DESC);
 MODULE_LICENSE("GPL");
 
-module_param(xmas, bool, S_IRUGO | S_IWUSR);
+module_param(xmas, bool, 0644);
 MODULE_PARM_DESC(xmas, "Xmas colors enabled or not");
 
-module_param(boost, int, S_IRUGO | S_IWUSR);
+module_param(boost, int, 0644);
 MODULE_PARM_DESC(boost, "Card overclock boost (in percent 100-500)");
 
-module_param(clockmode, int, S_IRUGO | S_IWUSR);
+module_param(clockmode, int, 0644);
 MODULE_PARM_DESC(clockmode, "Card clock mode (1=3.579 MHz, 2=3.680 MHz, "
 		"3=6 Mhz)");
 
-module_param(cdmode, int, S_IRUGO | S_IWUSR);
+module_param(cdmode, int, 0644);
 MODULE_PARM_DESC(cdmode, "Card detect mode (0=none, 1=CD, 2=!CD, 3=DSR, "
 		 "4=!DSR, 5=CTS, 6=!CTS, 7=RING, 8=!RING)");
 
-module_param(vcc_default, int, S_IRUGO | S_IWUSR);
+module_param(vcc_default, int, 0644);
 MODULE_PARM_DESC(vcc_default, "Set default VCC (either 3 for 3.3V or 5 "
 		"for 5V). Default to 5.");
diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
index 930b3d50a330..f45ca7ddf78e 100644
--- a/drivers/usb/serial/pl2303.c
+++ b/drivers/usb/serial/pl2303.c
@@ -433,6 +433,7 @@ static int pl2303_detect_type(struct usb_serial *serial)
 		switch (bcdDevice) {
 		case 0x100:
 		case 0x305:
+		case 0x405:
 			/*
 			 * Assume it's an HXN-type if the device doesn't
 			 * support the old read request value.
diff --git a/drivers/usb/serial/sierra.c b/drivers/usb/serial/sierra.c
index 4b49b7c33364..9d56138133a9 100644
--- a/drivers/usb/serial/sierra.c
+++ b/drivers/usb/serial/sierra.c
@@ -1056,5 +1056,5 @@ MODULE_AUTHOR(DRIVER_AUTHOR);
 MODULE_DESCRIPTION(DRIVER_DESC);
 MODULE_LICENSE("GPL v2");
 
-module_param(nmea, bool, S_IRUGO | S_IWUSR);
+module_param(nmea, bool, 0644);
 MODULE_PARM_DESC(nmea, "NMEA streaming");