USB: oti6858: use port write fifo

Kill private write fifo and use port fifo instead (protected under
port lock).

Compile-only tested.

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

1 files changed, 25 insertions, 37 deletions

diff --git a/drivers/usb/serial/oti6858.c b/drivers/usb/serial/oti6858.c
index a65be37bf129..e199b0f4f99c 100644
--- a/drivers/usb/serial/oti6858.c
+++ b/drivers/usb/serial/oti6858.c
@@ -76,8 +76,6 @@ static struct usb_driver oti6858_driver = {
 
 static int debug;
 
-#define OTI6858_FIFO_SIZE               1024
-
 /* requests */
 #define OTI6858_REQ_GET_STATUS          (USB_DIR_IN | USB_TYPE_VENDOR | 0x00)
 #define OTI6858_REQ_T_GET_STATUS        0x01
@@ -180,7 +178,6 @@ static struct usb_serial_driver oti6858_device = {
 struct oti6858_private {
         spinlock_t lock;
 
-        struct kfifo write_fifo;
         struct oti6858_control_pkt status;
 
         struct {
@@ -293,9 +290,12 @@ static void send_data(struct work_struct *work)
                 return;
         }
         priv->flags.write_urb_in_use = 1;
-
-        count = kfifo_len(&priv->write_fifo);
         spin_unlock_irqrestore(&priv->lock, flags);
+
+        spin_lock_irqsave(&port->lock, flags);
+        count = kfifo_len(&port->write_fifo);
+        spin_unlock_irqrestore(&port->lock, flags);
+
         if (count > port->bulk_out_size)
                 count = port->bulk_out_size;
 
@@ -329,9 +329,9 @@ static void send_data(struct work_struct *work)
                 return;
         }
 
-        count = kfifo_out_locked(&priv->write_fifo,
+        count = kfifo_out_locked(&port->write_fifo,
                                         port->write_urb->transfer_buffer,
-                                        count, &priv->lock);
+                                        count, &port->lock);
         port->write_urb->transfer_buffer_length = count;
         port->write_urb->dev = port->serial->dev;
         result = usb_submit_urb(port->write_urb, GFP_NOIO);
@@ -354,11 +354,6 @@ static int oti6858_startup(struct usb_serial *serial)
                 priv = kzalloc(sizeof(struct oti6858_private), GFP_KERNEL);
                 if (!priv)
                         break;
-                if (kfifo_alloc(&priv->write_fifo, OTI6858_FIFO_SIZE,
-                                                                GFP_KERNEL)) {
-                        kfree(priv);
-                        break;
-                }
 
                 spin_lock_init(&priv->lock);
                 init_waitqueue_head(&priv->intr_wait);
@@ -375,7 +370,6 @@ static int oti6858_startup(struct usb_serial *serial)
 
         for (--i; i >= 0; --i) {
                 priv = usb_get_serial_port_data(serial->port[i]);
-                kfifo_free(&priv->write_fifo);
                 kfree(priv);
                 usb_set_serial_port_data(serial->port[i], NULL);
         }
@@ -385,14 +379,12 @@ static int oti6858_startup(struct usb_serial *serial)
 static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
                         const unsigned char *buf, int count)
 {
-        struct oti6858_private *priv = usb_get_serial_port_data(port);
-
         dbg("%s(port = %d, count = %d)", __func__, port->number, count);
 
         if (!count)
                 return count;
 
-        count = kfifo_in_locked(&priv->write_fifo, buf, count, &priv->lock);
+        count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
 
         return count;
 }
@@ -400,15 +392,14 @@ static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
 static int oti6858_write_room(struct tty_struct *tty)
 {
         struct usb_serial_port *port = tty->driver_data;
-        struct oti6858_private *priv = usb_get_serial_port_data(port);
         int room = 0;
         unsigned long flags;
 
         dbg("%s(port = %d)", __func__, port->number);
 
-        spin_lock_irqsave(&priv->lock, flags);
-        room = kfifo_avail(&priv->write_fifo);
-        spin_unlock_irqrestore(&priv->lock, flags);
+        spin_lock_irqsave(&port->lock, flags);
+        room = kfifo_avail(&port->write_fifo);
+        spin_unlock_irqrestore(&port->lock, flags);
 
         return room;
 }
@@ -416,15 +407,14 @@ static int oti6858_write_room(struct tty_struct *tty)
 static int oti6858_chars_in_buffer(struct tty_struct *tty)
 {
         struct usb_serial_port *port = tty->driver_data;
-        struct oti6858_private *priv = usb_get_serial_port_data(port);
         int chars = 0;
         unsigned long flags;
 
         dbg("%s(port = %d)", __func__, port->number);
 
-        spin_lock_irqsave(&priv->lock, flags);
-        chars = kfifo_len(&priv->write_fifo);
-        spin_unlock_irqrestore(&priv->lock, flags);
+        spin_lock_irqsave(&port->lock, flags);
+        chars = kfifo_len(&port->write_fifo);
+        spin_unlock_irqrestore(&port->lock, flags);
 
         return chars;
 }
@@ -615,10 +605,10 @@ static void oti6858_close(struct usb_serial_port *port)
 
         dbg("%s(port = %d)", __func__, port->number);
 
-        spin_lock_irqsave(&priv->lock, flags);
+        spin_lock_irqsave(&port->lock, flags);
         /* clear out any remaining data in the buffer */
-        kfifo_reset_out(&priv->write_fifo);
-        spin_unlock_irqrestore(&priv->lock, flags);
+        kfifo_reset_out(&port->write_fifo);
+        spin_unlock_irqrestore(&port->lock, flags);
 
         dbg("%s(): after buf_clear()", __func__);
 
@@ -760,18 +750,12 @@ static int oti6858_ioctl(struct tty_struct *tty, struct file *file,
 
 static void oti6858_release(struct usb_serial *serial)
 {
-        struct oti6858_private *priv;
         int i;
 
         dbg("%s()", __func__);
 
-        for (i = 0; i < serial->num_ports; ++i) {
-                priv = usb_get_serial_port_data(serial->port[i]);
-                if (priv) {
-                        kfifo_free(&priv->write_fifo);
-                        kfree(priv);
-                }
-        }
+        for (i = 0; i < serial->num_ports; ++i)
+                kfree(usb_get_serial_port_data(serial->port[i]));
 }
 
 static void oti6858_read_int_callback(struct urb *urb)
@@ -864,10 +848,14 @@ static void oti6858_read_int_callback(struct urb *urb)
                 }
         } else if (!transient) {
                 unsigned long flags;
+                int count;
+
+                spin_lock_irqsave(&port->lock, flags);
+                count = kfifo_len(&port->write_fifo);
+                spin_unlock_irqrestore(&port->lock, flags);
 
                 spin_lock_irqsave(&priv->lock, flags);
-                if (priv->flags.write_urb_in_use == 0
-                                && kfifo_len(&priv->write_fifo) != 0) {
+                if (priv->flags.write_urb_in_use == 0 && count != 0) {
                         schedule_delayed_work(&priv->delayed_write_work, 0);
                         resubmit = 0;
                 }