mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-04 09:59:32 +00:00
![Oliver Neukum](/assets/img/avatar_default.png)
usb:usbserial:opticon: fix race between unthrottle and completion handler opticon_unthrottle() mustn't resubmit the URB unconditionally as the URB may still be running. Signed-off-by: Oliver Neukum <oliver@neukum.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
568 lines
14 KiB
C
568 lines
14 KiB
C
/*
|
|
* Opticon USB barcode to serial driver
|
|
*
|
|
* Copyright (C) 2008 - 2009 Greg Kroah-Hartman <gregkh@suse.de>
|
|
* Copyright (C) 2008 - 2009 Novell Inc.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License version
|
|
* 2 as published by the Free Software Foundation.
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/init.h>
|
|
#include <linux/tty.h>
|
|
#include <linux/tty_driver.h>
|
|
#include <linux/tty_flip.h>
|
|
#include <linux/serial.h>
|
|
#include <linux/module.h>
|
|
#include <linux/usb.h>
|
|
#include <linux/usb/serial.h>
|
|
#include <linux/uaccess.h>
|
|
|
|
static int debug;
|
|
|
|
static struct usb_device_id id_table[] = {
|
|
{ USB_DEVICE(0x065a, 0x0009) },
|
|
{ },
|
|
};
|
|
MODULE_DEVICE_TABLE(usb, id_table);
|
|
|
|
/* This structure holds all of the individual device information */
|
|
struct opticon_private {
|
|
struct usb_device *udev;
|
|
struct usb_serial *serial;
|
|
struct usb_serial_port *port;
|
|
unsigned char *bulk_in_buffer;
|
|
struct urb *bulk_read_urb;
|
|
int buffer_size;
|
|
u8 bulk_address;
|
|
spinlock_t lock; /* protects the following flags */
|
|
bool throttled;
|
|
bool actually_throttled;
|
|
bool rts;
|
|
int outstanding_urbs;
|
|
};
|
|
|
|
/* max number of write urbs in flight */
|
|
#define URB_UPPER_LIMIT 4
|
|
|
|
static void opticon_bulk_callback(struct urb *urb)
|
|
{
|
|
struct opticon_private *priv = urb->context;
|
|
unsigned char *data = urb->transfer_buffer;
|
|
struct usb_serial_port *port = priv->port;
|
|
int status = urb->status;
|
|
struct tty_struct *tty;
|
|
int result;
|
|
int available_room = 0;
|
|
int data_length;
|
|
|
|
dbg("%s - port %d", __func__, port->number);
|
|
|
|
switch (status) {
|
|
case 0:
|
|
/* success */
|
|
break;
|
|
case -ECONNRESET:
|
|
case -ENOENT:
|
|
case -ESHUTDOWN:
|
|
/* this urb is terminated, clean up */
|
|
dbg("%s - urb shutting down with status: %d",
|
|
__func__, status);
|
|
return;
|
|
default:
|
|
dbg("%s - nonzero urb status received: %d",
|
|
__func__, status);
|
|
goto exit;
|
|
}
|
|
|
|
usb_serial_debug_data(debug, &port->dev, __func__, urb->actual_length,
|
|
data);
|
|
|
|
if (urb->actual_length > 2) {
|
|
data_length = urb->actual_length - 2;
|
|
|
|
/*
|
|
* Data from the device comes with a 2 byte header:
|
|
*
|
|
* <0x00><0x00>data...
|
|
* This is real data to be sent to the tty layer
|
|
* <0x00><0x01)level
|
|
* This is a RTS level change, the third byte is the RTS
|
|
* value (0 for low, 1 for high).
|
|
*/
|
|
if ((data[0] == 0x00) && (data[1] == 0x00)) {
|
|
/* real data, send it to the tty layer */
|
|
tty = tty_port_tty_get(&port->port);
|
|
if (tty) {
|
|
available_room = tty_buffer_request_room(tty,
|
|
data_length);
|
|
if (available_room) {
|
|
tty_insert_flip_string(tty, data,
|
|
available_room);
|
|
tty_flip_buffer_push(tty);
|
|
}
|
|
tty_kref_put(tty);
|
|
}
|
|
} else {
|
|
if ((data[0] == 0x00) && (data[1] == 0x01)) {
|
|
if (data[2] == 0x00)
|
|
priv->rts = false;
|
|
else
|
|
priv->rts = true;
|
|
} else {
|
|
dev_dbg(&priv->udev->dev,
|
|
"Unknown data packet received from the device:"
|
|
" %2x %2x\n",
|
|
data[0], data[1]);
|
|
}
|
|
}
|
|
} else {
|
|
dev_dbg(&priv->udev->dev,
|
|
"Improper ammount of data received from the device, "
|
|
"%d bytes", urb->actual_length);
|
|
}
|
|
|
|
exit:
|
|
spin_lock(&priv->lock);
|
|
|
|
/* Continue trying to always read if we should */
|
|
if (!priv->throttled) {
|
|
usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
|
|
usb_rcvbulkpipe(priv->udev,
|
|
priv->bulk_address),
|
|
priv->bulk_in_buffer, priv->buffer_size,
|
|
opticon_bulk_callback, priv);
|
|
result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
|
|
if (result)
|
|
dev_err(&port->dev,
|
|
"%s - failed resubmitting read urb, error %d\n",
|
|
__func__, result);
|
|
} else
|
|
priv->actually_throttled = true;
|
|
spin_unlock(&priv->lock);
|
|
}
|
|
|
|
static int opticon_open(struct tty_struct *tty, struct usb_serial_port *port)
|
|
{
|
|
struct opticon_private *priv = usb_get_serial_data(port->serial);
|
|
unsigned long flags;
|
|
int result = 0;
|
|
|
|
dbg("%s - port %d", __func__, port->number);
|
|
|
|
spin_lock_irqsave(&priv->lock, flags);
|
|
priv->throttled = false;
|
|
priv->actually_throttled = false;
|
|
priv->port = port;
|
|
spin_unlock_irqrestore(&priv->lock, flags);
|
|
|
|
/* Start reading from the device */
|
|
usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
|
|
usb_rcvbulkpipe(priv->udev,
|
|
priv->bulk_address),
|
|
priv->bulk_in_buffer, priv->buffer_size,
|
|
opticon_bulk_callback, priv);
|
|
result = usb_submit_urb(priv->bulk_read_urb, GFP_KERNEL);
|
|
if (result)
|
|
dev_err(&port->dev,
|
|
"%s - failed resubmitting read urb, error %d\n",
|
|
__func__, result);
|
|
return result;
|
|
}
|
|
|
|
static void opticon_close(struct usb_serial_port *port)
|
|
{
|
|
struct opticon_private *priv = usb_get_serial_data(port->serial);
|
|
|
|
dbg("%s - port %d", __func__, port->number);
|
|
|
|
/* shutdown our urbs */
|
|
usb_kill_urb(priv->bulk_read_urb);
|
|
}
|
|
|
|
static void opticon_write_bulk_callback(struct urb *urb)
|
|
{
|
|
struct opticon_private *priv = urb->context;
|
|
int status = urb->status;
|
|
unsigned long flags;
|
|
|
|
/* free up the transfer buffer, as usb_free_urb() does not do this */
|
|
kfree(urb->transfer_buffer);
|
|
|
|
if (status)
|
|
dbg("%s - nonzero write bulk status received: %d",
|
|
__func__, status);
|
|
|
|
spin_lock_irqsave(&priv->lock, flags);
|
|
--priv->outstanding_urbs;
|
|
spin_unlock_irqrestore(&priv->lock, flags);
|
|
|
|
usb_serial_port_softint(priv->port);
|
|
}
|
|
|
|
static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
|
|
const unsigned char *buf, int count)
|
|
{
|
|
struct opticon_private *priv = usb_get_serial_data(port->serial);
|
|
struct usb_serial *serial = port->serial;
|
|
struct urb *urb;
|
|
unsigned char *buffer;
|
|
unsigned long flags;
|
|
int status;
|
|
|
|
dbg("%s - port %d", __func__, port->number);
|
|
|
|
spin_lock_irqsave(&priv->lock, flags);
|
|
if (priv->outstanding_urbs > URB_UPPER_LIMIT) {
|
|
spin_unlock_irqrestore(&priv->lock, flags);
|
|
dbg("%s - write limit hit\n", __func__);
|
|
return 0;
|
|
}
|
|
priv->outstanding_urbs++;
|
|
spin_unlock_irqrestore(&priv->lock, flags);
|
|
|
|
buffer = kmalloc(count, GFP_ATOMIC);
|
|
if (!buffer) {
|
|
dev_err(&port->dev, "out of memory\n");
|
|
count = -ENOMEM;
|
|
goto error_no_buffer;
|
|
}
|
|
|
|
urb = usb_alloc_urb(0, GFP_ATOMIC);
|
|
if (!urb) {
|
|
dev_err(&port->dev, "no more free urbs\n");
|
|
count = -ENOMEM;
|
|
goto error_no_urb;
|
|
}
|
|
|
|
memcpy(buffer, buf, count);
|
|
|
|
usb_serial_debug_data(debug, &port->dev, __func__, count, buffer);
|
|
|
|
usb_fill_bulk_urb(urb, serial->dev,
|
|
usb_sndbulkpipe(serial->dev,
|
|
port->bulk_out_endpointAddress),
|
|
buffer, count, opticon_write_bulk_callback, priv);
|
|
|
|
/* 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",
|
|
__func__, status);
|
|
count = status;
|
|
goto error;
|
|
}
|
|
|
|
/* 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;
|
|
error:
|
|
usb_free_urb(urb);
|
|
error_no_urb:
|
|
kfree(buffer);
|
|
error_no_buffer:
|
|
spin_lock_irqsave(&priv->lock, flags);
|
|
--priv->outstanding_urbs;
|
|
spin_unlock_irqrestore(&priv->lock, flags);
|
|
return count;
|
|
}
|
|
|
|
static int opticon_write_room(struct tty_struct *tty)
|
|
{
|
|
struct usb_serial_port *port = tty->driver_data;
|
|
struct opticon_private *priv = usb_get_serial_data(port->serial);
|
|
unsigned long flags;
|
|
|
|
dbg("%s - port %d", __func__, port->number);
|
|
|
|
/*
|
|
* We really can take almost anything the user throws at us
|
|
* but let's pick a nice big number to tell the tty
|
|
* layer that we have lots of free space, unless we don't.
|
|
*/
|
|
spin_lock_irqsave(&priv->lock, flags);
|
|
if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) {
|
|
spin_unlock_irqrestore(&priv->lock, flags);
|
|
dbg("%s - write limit hit\n", __func__);
|
|
return 0;
|
|
}
|
|
spin_unlock_irqrestore(&priv->lock, flags);
|
|
|
|
return 2048;
|
|
}
|
|
|
|
static void opticon_throttle(struct tty_struct *tty)
|
|
{
|
|
struct usb_serial_port *port = tty->driver_data;
|
|
struct opticon_private *priv = usb_get_serial_data(port->serial);
|
|
unsigned long flags;
|
|
|
|
dbg("%s - port %d", __func__, port->number);
|
|
spin_lock_irqsave(&priv->lock, flags);
|
|
priv->throttled = true;
|
|
spin_unlock_irqrestore(&priv->lock, flags);
|
|
}
|
|
|
|
|
|
static void opticon_unthrottle(struct tty_struct *tty)
|
|
{
|
|
struct usb_serial_port *port = tty->driver_data;
|
|
struct opticon_private *priv = usb_get_serial_data(port->serial);
|
|
unsigned long flags;
|
|
int result, was_throttled;
|
|
|
|
dbg("%s - port %d", __func__, port->number);
|
|
|
|
spin_lock_irqsave(&priv->lock, flags);
|
|
priv->throttled = false;
|
|
was_throttled = priv->actually_throttled;
|
|
priv->actually_throttled = false;
|
|
spin_unlock_irqrestore(&priv->lock, flags);
|
|
|
|
priv->bulk_read_urb->dev = port->serial->dev;
|
|
if (was_throttled) {
|
|
result = usb_submit_urb(priv->bulk_read_urb, GFP_ATOMIC);
|
|
if (result)
|
|
dev_err(&port->dev,
|
|
"%s - failed submitting read urb, error %d\n",
|
|
__func__, result);
|
|
}
|
|
}
|
|
|
|
static int opticon_tiocmget(struct tty_struct *tty, struct file *file)
|
|
{
|
|
struct usb_serial_port *port = tty->driver_data;
|
|
struct opticon_private *priv = usb_get_serial_data(port->serial);
|
|
unsigned long flags;
|
|
int result = 0;
|
|
|
|
dbg("%s - port %d", __func__, port->number);
|
|
|
|
spin_lock_irqsave(&priv->lock, flags);
|
|
if (priv->rts)
|
|
result = TIOCM_RTS;
|
|
spin_unlock_irqrestore(&priv->lock, flags);
|
|
|
|
dbg("%s - %x", __func__, result);
|
|
return result;
|
|
}
|
|
|
|
static int get_serial_info(struct opticon_private *priv,
|
|
struct serial_struct __user *serial)
|
|
{
|
|
struct serial_struct tmp;
|
|
|
|
if (!serial)
|
|
return -EFAULT;
|
|
|
|
memset(&tmp, 0x00, sizeof(tmp));
|
|
|
|
/* fake emulate a 16550 uart to make userspace code happy */
|
|
tmp.type = PORT_16550A;
|
|
tmp.line = priv->serial->minor;
|
|
tmp.port = 0;
|
|
tmp.irq = 0;
|
|
tmp.flags = ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
|
|
tmp.xmit_fifo_size = 1024;
|
|
tmp.baud_base = 9600;
|
|
tmp.close_delay = 5*HZ;
|
|
tmp.closing_wait = 30*HZ;
|
|
|
|
if (copy_to_user(serial, &tmp, sizeof(*serial)))
|
|
return -EFAULT;
|
|
return 0;
|
|
}
|
|
|
|
static int opticon_ioctl(struct tty_struct *tty, struct file *file,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct usb_serial_port *port = tty->driver_data;
|
|
struct opticon_private *priv = usb_get_serial_data(port->serial);
|
|
|
|
dbg("%s - port %d, cmd = 0x%x", __func__, port->number, cmd);
|
|
|
|
switch (cmd) {
|
|
case TIOCGSERIAL:
|
|
return get_serial_info(priv,
|
|
(struct serial_struct __user *)arg);
|
|
}
|
|
|
|
return -ENOIOCTLCMD;
|
|
}
|
|
|
|
static int opticon_startup(struct usb_serial *serial)
|
|
{
|
|
struct opticon_private *priv;
|
|
struct usb_host_interface *intf;
|
|
int i;
|
|
int retval = -ENOMEM;
|
|
bool bulk_in_found = false;
|
|
|
|
/* create our private serial structure */
|
|
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
|
|
if (priv == NULL) {
|
|
dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__);
|
|
return -ENOMEM;
|
|
}
|
|
spin_lock_init(&priv->lock);
|
|
priv->serial = serial;
|
|
priv->port = serial->port[0];
|
|
priv->udev = serial->dev;
|
|
|
|
/* find our bulk endpoint */
|
|
intf = serial->interface->altsetting;
|
|
for (i = 0; i < intf->desc.bNumEndpoints; ++i) {
|
|
struct usb_endpoint_descriptor *endpoint;
|
|
|
|
endpoint = &intf->endpoint[i].desc;
|
|
if (!usb_endpoint_is_bulk_in(endpoint))
|
|
continue;
|
|
|
|
priv->bulk_read_urb = usb_alloc_urb(0, GFP_KERNEL);
|
|
if (!priv->bulk_read_urb) {
|
|
dev_err(&priv->udev->dev, "out of memory\n");
|
|
goto error;
|
|
}
|
|
|
|
priv->buffer_size = le16_to_cpu(endpoint->wMaxPacketSize) * 2;
|
|
priv->bulk_in_buffer = kmalloc(priv->buffer_size, GFP_KERNEL);
|
|
if (!priv->bulk_in_buffer) {
|
|
dev_err(&priv->udev->dev, "out of memory\n");
|
|
goto error;
|
|
}
|
|
|
|
priv->bulk_address = endpoint->bEndpointAddress;
|
|
|
|
/* set up our bulk urb */
|
|
usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
|
|
usb_rcvbulkpipe(priv->udev,
|
|
endpoint->bEndpointAddress),
|
|
priv->bulk_in_buffer, priv->buffer_size,
|
|
opticon_bulk_callback, priv);
|
|
|
|
bulk_in_found = true;
|
|
break;
|
|
}
|
|
|
|
if (!bulk_in_found) {
|
|
dev_err(&priv->udev->dev,
|
|
"Error - the proper endpoints were not found!\n");
|
|
goto error;
|
|
}
|
|
|
|
usb_set_serial_data(serial, priv);
|
|
return 0;
|
|
|
|
error:
|
|
usb_free_urb(priv->bulk_read_urb);
|
|
kfree(priv->bulk_in_buffer);
|
|
kfree(priv);
|
|
return retval;
|
|
}
|
|
|
|
static void opticon_disconnect(struct usb_serial *serial)
|
|
{
|
|
struct opticon_private *priv = usb_get_serial_data(serial);
|
|
|
|
dbg("%s", __func__);
|
|
|
|
usb_kill_urb(priv->bulk_read_urb);
|
|
usb_free_urb(priv->bulk_read_urb);
|
|
}
|
|
|
|
static void opticon_release(struct usb_serial *serial)
|
|
{
|
|
struct opticon_private *priv = usb_get_serial_data(serial);
|
|
|
|
dbg("%s", __func__);
|
|
|
|
kfree(priv->bulk_in_buffer);
|
|
kfree(priv);
|
|
}
|
|
|
|
static int opticon_suspend(struct usb_interface *intf, pm_message_t message)
|
|
{
|
|
struct usb_serial *serial = usb_get_intfdata(intf);
|
|
struct opticon_private *priv = usb_get_serial_data(serial);
|
|
|
|
usb_kill_urb(priv->bulk_read_urb);
|
|
return 0;
|
|
}
|
|
|
|
static int opticon_resume(struct usb_interface *intf)
|
|
{
|
|
struct usb_serial *serial = usb_get_intfdata(intf);
|
|
struct opticon_private *priv = usb_get_serial_data(serial);
|
|
struct usb_serial_port *port = serial->port[0];
|
|
int result;
|
|
|
|
mutex_lock(&port->mutex);
|
|
if (port->port.count)
|
|
result = usb_submit_urb(priv->bulk_read_urb, GFP_NOIO);
|
|
else
|
|
result = 0;
|
|
mutex_unlock(&port->mutex);
|
|
return result;
|
|
}
|
|
|
|
static struct usb_driver opticon_driver = {
|
|
.name = "opticon",
|
|
.probe = usb_serial_probe,
|
|
.disconnect = usb_serial_disconnect,
|
|
.suspend = opticon_suspend,
|
|
.resume = opticon_resume,
|
|
.id_table = id_table,
|
|
.no_dynamic_id = 1,
|
|
};
|
|
|
|
static struct usb_serial_driver opticon_device = {
|
|
.driver = {
|
|
.owner = THIS_MODULE,
|
|
.name = "opticon",
|
|
},
|
|
.id_table = id_table,
|
|
.usb_driver = &opticon_driver,
|
|
.num_ports = 1,
|
|
.attach = opticon_startup,
|
|
.open = opticon_open,
|
|
.close = opticon_close,
|
|
.write = opticon_write,
|
|
.write_room = opticon_write_room,
|
|
.disconnect = opticon_disconnect,
|
|
.release = opticon_release,
|
|
.throttle = opticon_throttle,
|
|
.unthrottle = opticon_unthrottle,
|
|
.ioctl = opticon_ioctl,
|
|
.tiocmget = opticon_tiocmget,
|
|
};
|
|
|
|
static int __init opticon_init(void)
|
|
{
|
|
int retval;
|
|
|
|
retval = usb_serial_register(&opticon_device);
|
|
if (retval)
|
|
return retval;
|
|
retval = usb_register(&opticon_driver);
|
|
if (retval)
|
|
usb_serial_deregister(&opticon_device);
|
|
return retval;
|
|
}
|
|
|
|
static void __exit opticon_exit(void)
|
|
{
|
|
usb_deregister(&opticon_driver);
|
|
usb_serial_deregister(&opticon_device);
|
|
}
|
|
|
|
module_init(opticon_init);
|
|
module_exit(opticon_exit);
|
|
MODULE_LICENSE("GPL");
|
|
|
|
module_param(debug, bool, S_IRUGO | S_IWUSR);
|
|
MODULE_PARM_DESC(debug, "Debug enabled or not");
|