From 46dc0fc4befac07e71621d122a72194d2ae61c36 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Sun, 4 Jan 2015 18:45:37 +0100
Subject: [PATCH] USB: option: clean up blacklist handling

Clean up the unnecessarily complicated blacklist implementation
somewhat.

Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/usb/serial/option.c | 60 +++++++++----------------------------
 1 file changed, 14 insertions(+), 46 deletions(-)

diff --git a/drivers/usb/serial/option.c b/drivers/usb/serial/option.c
index efdcee15b520..f0c0c53359ad 100644
--- a/drivers/usb/serial/option.c
+++ b/drivers/usb/serial/option.c
@@ -507,18 +507,10 @@ static void option_instat_callback(struct urb *urb);
 #define VIATELECOM_VENDOR_ID			0x15eb
 #define VIATELECOM_PRODUCT_CDS7			0x0001
 
-/* some devices interfaces need special handling due to a number of reasons */
-enum option_blacklist_reason {
-		OPTION_BLACKLIST_NONE = 0,
-		OPTION_BLACKLIST_SENDSETUP = 1,
-		OPTION_BLACKLIST_RESERVED_IF = 2
-};
-
-#define MAX_BL_NUM  11
 struct option_blacklist_info {
-	/* bitfield of interface numbers for OPTION_BLACKLIST_SENDSETUP */
+	/* bitmask of interface numbers blacklisted for send_setup */
 	const unsigned long sendsetup;
-	/* bitfield of interface numbers for OPTION_BLACKLIST_RESERVED_IF */
+	/* bitmask of interface numbers that are reserved */
 	const unsigned long reserved;
 };
 
@@ -1822,36 +1814,13 @@ struct option_private {
 
 module_usb_serial_driver(serial_drivers, option_ids);
 
-static bool is_blacklisted(const u8 ifnum, enum option_blacklist_reason reason,
-			   const struct option_blacklist_info *blacklist)
-{
-	unsigned long num;
-	const unsigned long *intf_list;
-
-	if (blacklist) {
-		if (reason == OPTION_BLACKLIST_SENDSETUP)
-			intf_list = &blacklist->sendsetup;
-		else if (reason == OPTION_BLACKLIST_RESERVED_IF)
-			intf_list = &blacklist->reserved;
-		else {
-			BUG_ON(reason);
-			return false;
-		}
-
-		for_each_set_bit(num, intf_list, MAX_BL_NUM + 1) {
-			if (num == ifnum)
-				return true;
-		}
-	}
-	return false;
-}
-
 static int option_probe(struct usb_serial *serial,
 			const struct usb_device_id *id)
 {
 	struct usb_interface_descriptor *iface_desc =
 				&serial->interface->cur_altsetting->desc;
 	struct usb_device_descriptor *dev_desc = &serial->dev->descriptor;
+	const struct option_blacklist_info *blacklist;
 
 	/* Never bind to the CD-Rom emulation interface	*/
 	if (iface_desc->bInterfaceClass == 0x08)
@@ -1862,10 +1831,9 @@ static int option_probe(struct usb_serial *serial,
 	 * the same class/subclass/protocol as the serial interfaces.  Look at
 	 * the Windows driver .INF files for reserved interface numbers.
 	 */
-	if (is_blacklisted(
-		iface_desc->bInterfaceNumber,
-		OPTION_BLACKLIST_RESERVED_IF,
-		(const struct option_blacklist_info *) id->driver_info))
+	blacklist = (void *)id->driver_info;
+	if (blacklist && test_bit(iface_desc->bInterfaceNumber,
+						&blacklist->reserved))
 		return -ENODEV;
 	/*
 	 * Don't bind network interface on Samsung GT-B3730, it is handled by
@@ -1876,8 +1844,8 @@ static int option_probe(struct usb_serial *serial,
 	    iface_desc->bInterfaceClass != USB_CLASS_CDC_DATA)
 		return -ENODEV;
 
-	/* Store device id so we can use it during attach. */
-	usb_set_serial_data(serial, (void *)id);
+	/* Store the blacklist info so we can use it during attach. */
+	usb_set_serial_data(serial, (void *)blacklist);
 
 	return 0;
 }
@@ -1885,7 +1853,7 @@ static int option_probe(struct usb_serial *serial,
 static int option_attach(struct usb_serial *serial)
 {
 	struct usb_interface_descriptor *iface_desc;
-	const struct usb_device_id *id;
+	const struct option_blacklist_info *blacklist;
 	struct usb_wwan_intf_private *data;
 	struct option_private *priv;
 
@@ -1899,16 +1867,16 @@ static int option_attach(struct usb_serial *serial)
 		return -ENOMEM;
 	}
 
-	/* Retrieve device id stored at probe. */
-	id = usb_get_serial_data(serial);
+	/* Retrieve blacklist info stored at probe. */
+	blacklist = usb_get_serial_data(serial);
+
 	iface_desc = &serial->interface->cur_altsetting->desc;
 
 	priv->bInterfaceNumber = iface_desc->bInterfaceNumber;
 	data->private = priv;
 
-	if (!is_blacklisted(iface_desc->bInterfaceNumber,
-			OPTION_BLACKLIST_SENDSETUP,
-			(struct option_blacklist_info *)id->driver_info)) {
+	if (!blacklist || !test_bit(iface_desc->bInterfaceNumber,
+						&blacklist->sendsetup)) {
 		data->send_setup = option_send_setup;
 	}
 	spin_lock_init(&data->susp_lock);