xhci: dbgtty: use kfifo from tty_port struct

There is no need to define one in a custom structure. The tty_port one
is free to use.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Mathias Nyman <mathias.nyman@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
Link: https://lore.kernel.org/r/20240808103549.429349-6-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Jiri Slaby (SUSE)

drivers/usb/host/xhci-dbgcap.h

@@ -110,7 +110,6 @@ struct dbc_port {
 	struct tasklet_struct		push;
 
 	struct list_head		write_pool;
-	struct kfifo			write_fifo;
 
 	bool				registered;
 };

drivers/usb/host/xhci-dbgtty.c

@@ -36,7 +36,7 @@ static int dbc_start_tx(struct dbc_port *port)
 
 	while (!list_empty(pool)) {
 		req = list_entry(pool->next, struct dbc_request, list_pool);
-		len = kfifo_out(&port->write_fifo, req->buf, DBC_MAX_PACKET);
+		len = kfifo_out(&port->port.xmit_fifo, req->buf, DBC_MAX_PACKET);
 		if (len == 0)
 			break;
 		do_tty_wake = true;
@@ -203,7 +203,7 @@ static ssize_t dbc_tty_write(struct tty_struct *tty, const u8 *buf,
 
 	spin_lock_irqsave(&port->port_lock, flags);
 	if (count)
-		count = kfifo_in(&port->write_fifo, buf, count);
+		count = kfifo_in(&port->port.xmit_fifo, buf, count);
 	dbc_start_tx(port);
 	spin_unlock_irqrestore(&port->port_lock, flags);
 
@@ -217,7 +217,7 @@ static int dbc_tty_put_char(struct tty_struct *tty, u8 ch)
 	int			status;
 
 	spin_lock_irqsave(&port->port_lock, flags);
-	status = kfifo_put(&port->write_fifo, ch);
+	status = kfifo_put(&port->port.xmit_fifo, ch);
 	spin_unlock_irqrestore(&port->port_lock, flags);
 
 	return status;
@@ -240,7 +240,7 @@ static unsigned int dbc_tty_write_room(struct tty_struct *tty)
 	unsigned int		room;
 
 	spin_lock_irqsave(&port->port_lock, flags);
-	room = kfifo_avail(&port->write_fifo);
+	room = kfifo_avail(&port->port.xmit_fifo);
 	spin_unlock_irqrestore(&port->port_lock, flags);
 
 	return room;
@@ -253,7 +253,7 @@ static unsigned int dbc_tty_chars_in_buffer(struct tty_struct *tty)
 	unsigned int		chars;
 
 	spin_lock_irqsave(&port->port_lock, flags);
-	chars = kfifo_len(&port->write_fifo);
+	chars = kfifo_len(&port->port.xmit_fifo);
 	spin_unlock_irqrestore(&port->port_lock, flags);
 
 	return chars;
@@ -411,7 +411,8 @@ static int xhci_dbc_tty_register_device(struct xhci_dbc *dbc)
 		goto err_idr;
 	}
 
-	ret = kfifo_alloc(&port->write_fifo, DBC_WRITE_BUF_SIZE, GFP_KERNEL);
+	ret = kfifo_alloc(&port->port.xmit_fifo, DBC_WRITE_BUF_SIZE,
+			  GFP_KERNEL);
 	if (ret)
 		goto err_exit_port;
 
@@ -440,7 +441,7 @@ static int xhci_dbc_tty_register_device(struct xhci_dbc *dbc)
 	xhci_dbc_free_requests(&port->read_pool);
 	xhci_dbc_free_requests(&port->write_pool);
 err_free_fifo:
-	kfifo_free(&port->write_fifo);
+	kfifo_free(&port->port.xmit_fifo);
 err_exit_port:
 	idr_remove(&dbc_tty_minors, port->minor);
 err_idr:
@@ -465,7 +466,7 @@ static void xhci_dbc_tty_unregister_device(struct xhci_dbc *dbc)
 	idr_remove(&dbc_tty_minors, port->minor);
 	mutex_unlock(&dbc_tty_minors_lock);
 
-	kfifo_free(&port->write_fifo);
+	kfifo_free(&port->port.xmit_fifo);
 	xhci_dbc_free_requests(&port->read_pool);
 	xhci_dbc_free_requests(&port->read_queue);
 	xhci_dbc_free_requests(&port->write_pool);