USB: kobil_sct: use port interrupt-out urb

Use the port interrupt-out urb rather than abusing the port write_urb
pointer and allocating a new urb at every open (but the first...).

Note that the write_urb abuse would have led to a double free should
there ever be interfaces with a bulk-out endpoint.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 8 insertions, 67 deletions

diff --git a/drivers/usb/serial/kobil_sct.c b/drivers/usb/serial/kobil_sct.c
index 5bcfd57267f7..78b48c31abf5 100644
--- a/drivers/usb/serial/kobil_sct.c
+++ b/drivers/usb/serial/kobil_sct.c
@@ -65,7 +65,7 @@ static int  kobil_tiocmget(struct tty_struct *tty);
 static int  kobil_tiocmset(struct tty_struct *tty,
                            unsigned int set, unsigned int clear);
 static void kobil_read_int_callback(struct urb *urb);
-static void kobil_write_callback(struct urb *purb);
+static void kobil_write_int_callback(struct urb *urb);
 static void kobil_set_termios(struct tty_struct *tty,
                         struct usb_serial_port *port, struct ktermios *old);
 static void kobil_init_termios(struct tty_struct *tty);
@@ -99,6 +99,7 @@ static struct usb_serial_driver kobil_device = {
         .write =                kobil_write,
         .write_room =           kobil_write_room,
         .read_int_callback =    kobil_read_int_callback,
+        .write_int_callback =   kobil_write_int_callback,
 };
 
 static struct usb_serial_driver * const serial_drivers[] = {
@@ -106,7 +107,6 @@ static struct usb_serial_driver * const serial_drivers[] = {
 };
 
 struct kobil_private {
-        int write_int_endpoint_address;
         unsigned char buf[KOBIL_BUF_LENGTH]; /* buffer for the APDU to send */
         int filled;  /* index of the last char in buf */
         int cur_pos; /* index of the next char to send in buf */
@@ -116,14 +116,8 @@ struct kobil_private {
 
 static int kobil_port_probe(struct usb_serial_port *port)
 {
-        int i;
         struct usb_serial *serial = port->serial;
         struct kobil_private *priv;
-        struct usb_device *pdev;
-        struct usb_host_config *actconfig;
-        struct usb_interface *interface;
-        struct usb_host_interface *altsetting;
-        struct usb_host_endpoint *endpoint;
 
         priv = kmalloc(sizeof(struct kobil_private), GFP_KERNEL);
         if (!priv)
@@ -149,23 +143,6 @@ static int kobil_port_probe(struct usb_serial_port *port)
         }
         usb_set_serial_port_data(port, priv);
 
-        /* search for the necessary endpoints */
-        pdev = serial->dev;
-        actconfig = pdev->actconfig;
-        interface = actconfig->interface[0];
-        altsetting = interface->cur_altsetting;
-        endpoint = altsetting->endpoint;
-
-        for (i = 0; i < altsetting->desc.bNumEndpoints; i++) {
-                endpoint = &altsetting->endpoint[i];
-                if (usb_endpoint_is_int_out(&endpoint->desc)) {
-                        dev_dbg(&serial->dev->dev,
-                                "%s Found interrupt out endpoint. Address: %d\n",
-                                __func__, endpoint->desc.bEndpointAddress);
-                        priv->write_int_endpoint_address =
-                                endpoint->desc.bEndpointAddress;
-                }
-        }
         return 0;
 }
 
@@ -197,7 +174,6 @@ static int kobil_open(struct tty_struct *tty, struct usb_serial_port *port)
         struct kobil_private *priv;
         unsigned char *transfer_buffer;
         int transfer_buffer_length = 8;
-        int write_urb_transfer_buffer_length = 8;
 
         priv = usb_get_serial_port_data(port);
 
@@ -206,27 +182,6 @@ static int kobil_open(struct tty_struct *tty, struct usb_serial_port *port)
         if (!transfer_buffer)
                 return -ENOMEM;
 
-        /* allocate write_urb */
-        if (!port->write_urb) {
-                dev_dbg(dev, "%s - Allocating port->write_urb\n", __func__);
-                port->write_urb = usb_alloc_urb(0, GFP_KERNEL);
-                if (!port->write_urb) {
-                        dev_dbg(dev, "%s - usb_alloc_urb failed\n", __func__);
-                        kfree(transfer_buffer);
-                        return -ENOMEM;
-                }
-        }
-
-        /* allocate memory for write_urb transfer buffer */
-        port->write_urb->transfer_buffer =
-                        kmalloc(write_urb_transfer_buffer_length, GFP_KERNEL);
-        if (!port->write_urb->transfer_buffer) {
-                kfree(transfer_buffer);
-                usb_free_urb(port->write_urb);
-                port->write_urb = NULL;
-                return -ENOMEM;
-        }
-
         /* get hardware version */
         result = usb_control_msg(port->serial->dev,
                           usb_rcvctrlpipe(port->serial->dev, 0),
@@ -302,12 +257,7 @@ static int kobil_open(struct tty_struct *tty, struct usb_serial_port *port)
 static void kobil_close(struct usb_serial_port *port)
 {
         /* FIXME: Add rts/dtr methods */
-        if (port->write_urb) {
-                usb_poison_urb(port->write_urb);
-                kfree(port->write_urb->transfer_buffer);
-                usb_free_urb(port->write_urb);
-                port->write_urb = NULL;
-        }
+        usb_kill_urb(port->interrupt_out_urb);
         usb_kill_urb(port->interrupt_in_urb);
 }
 
@@ -336,7 +286,7 @@ static void kobil_read_int_callback(struct urb *urb)
 }
 
 
-static void kobil_write_callback(struct urb *purb)
+static void kobil_write_int_callback(struct urb *urb)
 {
 }
 
@@ -379,23 +329,14 @@ static int kobil_write(struct tty_struct *tty, struct usb_serial_port *port,
 
                 while (todo > 0) {
                         /* max 8 byte in one urb (endpoint size) */
-                        length = (todo < 8) ? todo : 8;
+                        length = min(todo, port->interrupt_out_size);
                         /* copy data to transfer buffer */
-                        memcpy(port->write_urb->transfer_buffer,
+                        memcpy(port->interrupt_out_buffer,
                                         priv->buf + priv->cur_pos, length);
-                        usb_fill_int_urb(port->write_urb,
-                                  port->serial->dev,
-                                  usb_sndintpipe(port->serial->dev,
-                                        priv->write_int_endpoint_address),
-                                  port->write_urb->transfer_buffer,
-                                  length,
-                                  kobil_write_callback,
-                                  port,
-                                  8
-                        );
+                        port->interrupt_out_urb->transfer_buffer_length = length;
 
                         priv->cur_pos = priv->cur_pos + length;
-                        result = usb_submit_urb(port->write_urb, GFP_NOIO);
+                        result = usb_submit_urb(port->interrupt_out_urb, GFP_NOIO);
                         dev_dbg(&port->dev, "%s - Send write URB returns: %i\n", __func__, result);
                         todo = priv->filled - priv->cur_pos;