path: root/usb/airprime_major_update.patch

From foo@baz Tue Apr  9 12:12:43 2002
Date: Wed, 31 May 2006 20:16:19 +0200
To: Greg KH <greg@kroah.com>
From: Greg Kroah-Hartman <gregkh@suse.de>
Subject: USB: big airprime driver update

This should make the airprime driver work much faster and hopefully
achieve wire speeds.  It increases the buffer size of the urbs and puts
lots of them in flight at the same time.

Thanks to Ken Brush <kbrush@gmail.com> for help in testing this.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


---
 drivers/usb/serial/airprime.c |  206 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 205 insertions(+), 1 deletion(-)

--- gregkh-2.6.orig/drivers/usb/serial/airprime.c
+++ gregkh-2.6/drivers/usb/serial/airprime.c
@@ -1,7 +1,7 @@
 /*
  * AirPrime CDMA Wireless Serial USB driver
  *
- * Copyright (C) 2005 Greg Kroah-Hartman <gregkh@suse.de>
+ * Copyright (C) 2005-2006 Greg Kroah-Hartman <gregkh@suse.de>
  *
  *	This program is free software; you can redistribute it and/or
  *	modify it under the terms of the GNU General Public License version
@@ -11,6 +11,7 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/tty.h>
+#include <linux/tty_flip.h>
 #include <linux/module.h>
 #include <linux/usb.h>
 #include "usb-serial.h"
@@ -25,6 +26,201 @@ static struct usb_device_id id_table [] 
 };
 MODULE_DEVICE_TABLE(usb, id_table);
 
+#define URB_TRANSFER_BUFFER_SIZE	4096
+#define NUM_READ_URBS			4
+#define NUM_WRITE_URBS			4
+
+/* if overridden by the user, then use their value for the size of the
+ * read and write urbs */
+static int buffer_size = URB_TRANSFER_BUFFER_SIZE;
+static int debug;
+
+struct airprime_private {
+	spinlock_t lock;
+	int outstanding_urbs;
+	int throttled;
+};
+
+static void airprime_read_bulk_callback(struct urb *urb, struct pt_regs *regs)
+{
+	struct usb_serial_port *port = urb->context;
+	unsigned char *data = urb->transfer_buffer;
+	struct tty_struct *tty;
+	int result;
+
+	dbg("%s - port %d", __FUNCTION__, port->number);
+
+	if (urb->status) {
+		dbg("%s - nonzero read bulk status received: %d",
+		    __FUNCTION__, urb->status);
+		/* something happened, so free up the memory for this urb (the
+		 * urb will go away automatically when we return due to the
+		 * reference count drop. */
+		kfree(urb->transfer_buffer);
+		return;
+	}
+
+	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
+
+	tty = port->tty;
+	if (tty && urb->actual_length) {
+		tty_buffer_request_room(tty, urb->actual_length);
+		tty_insert_flip_string(tty, data, urb->actual_length);
+		tty_flip_buffer_push(tty);
+	}
+
+	result = usb_submit_urb(urb, GFP_ATOMIC);
+	if (result)
+		dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n",
+			__FUNCTION__, result);
+	return;
+}
+
+static void airprime_write_bulk_callback(struct urb *urb, struct pt_regs *regs)
+{
+	struct usb_serial_port *port = urb->context;
+	struct airprime_private *priv = usb_get_serial_port_data(port);
+	unsigned long flags;
+
+	/* free up the transfer buffer, as usb_free_urb() does not do this */
+	kfree (urb->transfer_buffer);
+
+	dbg("%s - port %d", __FUNCTION__, port->number);
+
+	if (urb->status)
+		dbg("%s - nonzero write bulk status received: %d",
+		    __FUNCTION__, urb->status);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	--priv->outstanding_urbs;
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	usb_serial_port_softint(port);
+}
+
+static int airprime_open(struct usb_serial_port *port, struct file *filp)
+{
+	struct airprime_private *priv = usb_get_serial_port_data(port);
+	struct usb_serial *serial = port->serial;
+	struct urb *urb;
+	char *buffer;
+	int i;
+	int result = 0;
+
+	dbg("%s - port %d", __FUNCTION__, port->number);
+
+	/* initialize our private data structure if it isn't already created */
+	if (!priv) {
+		priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+		if (!priv)
+			return -ENOMEM;
+		spin_lock_init(&priv->lock);
+		usb_set_serial_port_data(port, priv);
+	}
+
+	/* TODO handle error conditions better, right now we leak memory */
+	for (i = 0; i < NUM_READ_URBS; ++i) {
+		buffer = kmalloc(buffer_size, GFP_KERNEL);
+		if (!buffer) {
+			dev_err(&port->dev, "%s - out of memory.\n",
+				__FUNCTION__);
+			return -ENOMEM;
+		}
+		urb = usb_alloc_urb(0, GFP_KERNEL);
+		if (!urb) {
+			dev_err(&port->dev, "%s - no more urbs?\n",
+				__FUNCTION__);
+			return -ENOMEM;
+		}
+		usb_fill_bulk_urb(urb, serial->dev,
+				  usb_rcvbulkpipe(serial->dev,
+				  		  port->bulk_out_endpointAddress),
+				  buffer, buffer_size,
+				  airprime_read_bulk_callback, port);
+		result = usb_submit_urb(urb, GFP_KERNEL);
+		if (result) {
+			dev_err(&port->dev,
+				"%s - failed submitting read urb, error %d\n",
+				__FUNCTION__, result);
+			return result;
+		}
+		/* fun with reference counting, when this urb is finished, the
+		 * host driver will free it up automatically */
+		usb_free_urb (urb);
+	}
+
+	return result;
+}
+
+static void airprime_close(struct usb_serial_port *port, struct file * filp)
+{
+	/* free up private structure? */
+}
+
+static int airprime_write(struct usb_serial_port *port,
+			  const unsigned char *buf, int count)
+{
+	struct airprime_private *priv = usb_get_serial_port_data(port);
+	struct usb_serial *serial = port->serial;
+	struct urb *urb;
+	unsigned char *buffer;
+	unsigned long flags;
+	int status;
+
+	dbg("%s - port %d", __FUNCTION__, port->number);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (priv->outstanding_urbs > NUM_WRITE_URBS) {
+		spin_unlock_irqrestore(&priv->lock, flags);
+		dbg("%s - write limit hit\n", __FUNCTION__);
+		return 0;
+	}
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	buffer = kmalloc(count, GFP_ATOMIC);
+	if (!buffer) {
+		dev_err(&port->dev, "out of memory\n");
+		return -ENOMEM;
+	}
+
+	urb = usb_alloc_urb(0, GFP_ATOMIC);
+	if (!urb) {
+		dev_err(&port->dev, "no more free urbs\n");
+		kfree (buffer);
+		return -ENOMEM;
+	}
+
+	memcpy (buffer, buf, count);
+
+	usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, buffer);
+
+	usb_fill_bulk_urb(urb, serial->dev,
+			  usb_sndbulkpipe(serial->dev,
+					  port->bulk_out_endpointAddress),
+			  buffer, count,
+			  airprime_write_bulk_callback, port);
+
+	/* send it down the pipe */
+	status = usb_submit_urb(urb, GFP_ATOMIC);
+	if (status) {
+		dev_err(&port->dev, "%s - usb_submit_urb(write bulk) failed with status = %d\n",
+			__FUNCTION__, status);
+		count = status;
+		kfree (buffer);
+	} else {
+		spin_lock_irqsave(&priv->lock, flags);
+		++priv->outstanding_urbs;
+		spin_unlock_irqrestore(&priv->lock, flags);
+	}
+
+	/* we are done with this urb, so let the host driver
+	 * really free it when it is finished with it */
+	usb_free_urb (urb);
+
+	return count;
+}
+
+
 static struct usb_driver airprime_driver = {
 	.name =		"airprime",
 	.probe =	usb_serial_probe,
@@ -43,6 +239,9 @@ static struct usb_serial_driver airprime
 	.num_bulk_in =		NUM_DONT_CARE,
 	.num_bulk_out =		NUM_DONT_CARE,
 	.num_ports =		1,
+	.open =			airprime_open,
+	.close =		airprime_close,
+	.write =		airprime_write,
 };
 
 static int __init airprime_init(void)
@@ -67,3 +266,8 @@ static void __exit airprime_exit(void)
 module_init(airprime_init);
 module_exit(airprime_exit);
 MODULE_LICENSE("GPL");
+
+module_param(debug, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug, "Debug enabled or not");
+module_param(buffer_size, int, 0);
+MODULE_PARM_DESC(buffer_size, "Size of the transfer buffers");