mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 09:19:51 +00:00
![Johan Hovold](/assets/img/avatar_default.png)
As David VomLehn points out, it was possible to receive an interrupt before clearing the free-urb flag which could lead to the urb being incorrectly marked as busy. For the same reason, move tx_bytes accounting so that it will never be negative. Note that the free-flags set and clear operations do not need any additional locking as they are manipulated while USB_SERIAL_WRITE_BUSY is set. Reported-by: David VomLehn <dvomlehn@cisco.com> Tested-by: David VomLehn <dvomlehn@cisco.com> Signed-off-by: Johan Hovold <jhovold@gmail.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
525 lines
13 KiB
C
525 lines
13 KiB
C
/*
|
|
* USB Serial Converter Generic functions
|
|
*
|
|
* Copyright (C) 2010 Johan Hovold (jhovold@gmail.com)
|
|
* Copyright (C) 1999 - 2002 Greg Kroah-Hartman (greg@kroah.com)
|
|
*
|
|
* 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/errno.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/sysrq.h>
|
|
#include <linux/tty.h>
|
|
#include <linux/tty_flip.h>
|
|
#include <linux/module.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/usb.h>
|
|
#include <linux/usb/serial.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/kfifo.h>
|
|
#include <linux/serial.h>
|
|
|
|
static int debug;
|
|
|
|
#ifdef CONFIG_USB_SERIAL_GENERIC
|
|
|
|
static int generic_probe(struct usb_interface *interface,
|
|
const struct usb_device_id *id);
|
|
|
|
static __u16 vendor = 0x05f9;
|
|
static __u16 product = 0xffff;
|
|
|
|
module_param(vendor, ushort, 0);
|
|
MODULE_PARM_DESC(vendor, "User specified USB idVendor");
|
|
|
|
module_param(product, ushort, 0);
|
|
MODULE_PARM_DESC(product, "User specified USB idProduct");
|
|
|
|
static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */
|
|
|
|
/* we want to look at all devices, as the vendor/product id can change
|
|
* depending on the command line argument */
|
|
static const struct usb_device_id generic_serial_ids[] = {
|
|
{.driver_info = 42},
|
|
{}
|
|
};
|
|
|
|
static struct usb_driver generic_driver = {
|
|
.name = "usbserial_generic",
|
|
.probe = generic_probe,
|
|
.disconnect = usb_serial_disconnect,
|
|
.id_table = generic_serial_ids,
|
|
.no_dynamic_id = 1,
|
|
};
|
|
|
|
/* All of the device info needed for the Generic Serial Converter */
|
|
struct usb_serial_driver usb_serial_generic_device = {
|
|
.driver = {
|
|
.owner = THIS_MODULE,
|
|
.name = "generic",
|
|
},
|
|
.id_table = generic_device_ids,
|
|
.usb_driver = &generic_driver,
|
|
.num_ports = 1,
|
|
.disconnect = usb_serial_generic_disconnect,
|
|
.release = usb_serial_generic_release,
|
|
.throttle = usb_serial_generic_throttle,
|
|
.unthrottle = usb_serial_generic_unthrottle,
|
|
.resume = usb_serial_generic_resume,
|
|
};
|
|
|
|
static int generic_probe(struct usb_interface *interface,
|
|
const struct usb_device_id *id)
|
|
{
|
|
const struct usb_device_id *id_pattern;
|
|
|
|
id_pattern = usb_match_id(interface, generic_device_ids);
|
|
if (id_pattern != NULL)
|
|
return usb_serial_probe(interface, id);
|
|
return -ENODEV;
|
|
}
|
|
#endif
|
|
|
|
int usb_serial_generic_register(int _debug)
|
|
{
|
|
int retval = 0;
|
|
|
|
debug = _debug;
|
|
#ifdef CONFIG_USB_SERIAL_GENERIC
|
|
generic_device_ids[0].idVendor = vendor;
|
|
generic_device_ids[0].idProduct = product;
|
|
generic_device_ids[0].match_flags =
|
|
USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT;
|
|
|
|
/* register our generic driver with ourselves */
|
|
retval = usb_serial_register(&usb_serial_generic_device);
|
|
if (retval)
|
|
goto exit;
|
|
retval = usb_register(&generic_driver);
|
|
if (retval)
|
|
usb_serial_deregister(&usb_serial_generic_device);
|
|
exit:
|
|
#endif
|
|
return retval;
|
|
}
|
|
|
|
void usb_serial_generic_deregister(void)
|
|
{
|
|
#ifdef CONFIG_USB_SERIAL_GENERIC
|
|
/* remove our generic driver */
|
|
usb_deregister(&generic_driver);
|
|
usb_serial_deregister(&usb_serial_generic_device);
|
|
#endif
|
|
}
|
|
|
|
int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port)
|
|
{
|
|
int result = 0;
|
|
unsigned long flags;
|
|
|
|
dbg("%s - port %d", __func__, port->number);
|
|
|
|
/* clear the throttle flags */
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
port->throttled = 0;
|
|
port->throttle_req = 0;
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
|
|
/* if we have a bulk endpoint, start reading from it */
|
|
if (port->bulk_in_size)
|
|
result = usb_serial_generic_submit_read_urb(port, GFP_KERNEL);
|
|
|
|
return result;
|
|
}
|
|
EXPORT_SYMBOL_GPL(usb_serial_generic_open);
|
|
|
|
static void generic_cleanup(struct usb_serial_port *port)
|
|
{
|
|
struct usb_serial *serial = port->serial;
|
|
unsigned long flags;
|
|
int i;
|
|
|
|
dbg("%s - port %d", __func__, port->number);
|
|
|
|
if (serial->dev) {
|
|
/* shutdown any bulk transfers that might be going on */
|
|
if (port->bulk_out_size) {
|
|
usb_kill_urb(port->write_urb);
|
|
for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
|
|
usb_kill_urb(port->write_urbs[i]);
|
|
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
kfifo_reset_out(&port->write_fifo);
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
}
|
|
if (port->bulk_in_size)
|
|
usb_kill_urb(port->read_urb);
|
|
}
|
|
}
|
|
|
|
void usb_serial_generic_close(struct usb_serial_port *port)
|
|
{
|
|
dbg("%s - port %d", __func__, port->number);
|
|
generic_cleanup(port);
|
|
}
|
|
EXPORT_SYMBOL_GPL(usb_serial_generic_close);
|
|
|
|
int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port,
|
|
void *dest, size_t size)
|
|
{
|
|
return kfifo_out_locked(&port->write_fifo, dest, size, &port->lock);
|
|
}
|
|
|
|
/**
|
|
* usb_serial_generic_write_start - kick off an URB write
|
|
* @port: Pointer to the &struct usb_serial_port data
|
|
*
|
|
* Returns zero on success, or a negative errno value
|
|
*/
|
|
static int usb_serial_generic_write_start(struct usb_serial_port *port)
|
|
{
|
|
struct urb *urb;
|
|
int count, result;
|
|
unsigned long flags;
|
|
int i;
|
|
|
|
if (test_and_set_bit_lock(USB_SERIAL_WRITE_BUSY, &port->flags))
|
|
return 0;
|
|
retry:
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
if (!port->write_urbs_free || !kfifo_len(&port->write_fifo)) {
|
|
clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
return 0;
|
|
}
|
|
i = (int)find_first_bit(&port->write_urbs_free,
|
|
ARRAY_SIZE(port->write_urbs));
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
|
|
urb = port->write_urbs[i];
|
|
count = port->serial->type->prepare_write_buffer(port,
|
|
urb->transfer_buffer,
|
|
port->bulk_out_size);
|
|
urb->transfer_buffer_length = count;
|
|
usb_serial_debug_data(debug, &port->dev, __func__, count,
|
|
urb->transfer_buffer);
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
port->tx_bytes += count;
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
|
|
clear_bit(i, &port->write_urbs_free);
|
|
result = usb_submit_urb(urb, GFP_ATOMIC);
|
|
if (result) {
|
|
dev_err(&port->dev, "%s - error submitting urb: %d\n",
|
|
__func__, result);
|
|
set_bit(i, &port->write_urbs_free);
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
port->tx_bytes -= count;
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
|
|
clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
|
|
return result;
|
|
}
|
|
|
|
/* Try sending off another urb, unless in irq context (in which case
|
|
* there will be no free urb). */
|
|
if (!in_irq())
|
|
goto retry;
|
|
|
|
clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* usb_serial_generic_write - generic write function for serial USB devices
|
|
* @tty: Pointer to &struct tty_struct for the device
|
|
* @port: Pointer to the &usb_serial_port structure for the device
|
|
* @buf: Pointer to the data to write
|
|
* @count: Number of bytes to write
|
|
*
|
|
* Returns the number of characters actually written, which may be anything
|
|
* from zero to @count. If an error occurs, it returns the negative errno
|
|
* value.
|
|
*/
|
|
int usb_serial_generic_write(struct tty_struct *tty,
|
|
struct usb_serial_port *port, const unsigned char *buf, int count)
|
|
{
|
|
int result;
|
|
|
|
dbg("%s - port %d", __func__, port->number);
|
|
|
|
/* only do something if we have a bulk out endpoint */
|
|
if (!port->bulk_out_size)
|
|
return -ENODEV;
|
|
|
|
if (!count)
|
|
return 0;
|
|
|
|
count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
|
|
result = usb_serial_generic_write_start(port);
|
|
if (result)
|
|
return result;
|
|
|
|
return count;
|
|
}
|
|
EXPORT_SYMBOL_GPL(usb_serial_generic_write);
|
|
|
|
int usb_serial_generic_write_room(struct tty_struct *tty)
|
|
{
|
|
struct usb_serial_port *port = tty->driver_data;
|
|
unsigned long flags;
|
|
int room;
|
|
|
|
dbg("%s - port %d", __func__, port->number);
|
|
|
|
if (!port->bulk_out_size)
|
|
return 0;
|
|
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
room = kfifo_avail(&port->write_fifo);
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
|
|
dbg("%s - returns %d", __func__, room);
|
|
return room;
|
|
}
|
|
|
|
int usb_serial_generic_chars_in_buffer(struct tty_struct *tty)
|
|
{
|
|
struct usb_serial_port *port = tty->driver_data;
|
|
unsigned long flags;
|
|
int chars;
|
|
|
|
dbg("%s - port %d", __func__, port->number);
|
|
|
|
if (!port->bulk_out_size)
|
|
return 0;
|
|
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
chars = kfifo_len(&port->write_fifo) + port->tx_bytes;
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
|
|
dbg("%s - returns %d", __func__, chars);
|
|
return chars;
|
|
}
|
|
|
|
int usb_serial_generic_submit_read_urb(struct usb_serial_port *port,
|
|
gfp_t mem_flags)
|
|
{
|
|
int result;
|
|
|
|
result = usb_submit_urb(port->read_urb, mem_flags);
|
|
if (result && result != -EPERM) {
|
|
dev_err(&port->dev, "%s - error submitting urb: %d\n",
|
|
__func__, result);
|
|
}
|
|
return result;
|
|
}
|
|
EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urb);
|
|
|
|
void usb_serial_generic_process_read_urb(struct urb *urb)
|
|
{
|
|
struct usb_serial_port *port = urb->context;
|
|
struct tty_struct *tty;
|
|
char *ch = (char *)urb->transfer_buffer;
|
|
int i;
|
|
|
|
if (!urb->actual_length)
|
|
return;
|
|
|
|
tty = tty_port_tty_get(&port->port);
|
|
if (!tty)
|
|
return;
|
|
|
|
/* The per character mucking around with sysrq path it too slow for
|
|
stuff like 3G modems, so shortcircuit it in the 99.9999999% of cases
|
|
where the USB serial is not a console anyway */
|
|
if (!port->port.console || !port->sysrq)
|
|
tty_insert_flip_string(tty, ch, urb->actual_length);
|
|
else {
|
|
for (i = 0; i < urb->actual_length; i++, ch++) {
|
|
if (!usb_serial_handle_sysrq_char(tty, port, *ch))
|
|
tty_insert_flip_char(tty, *ch, TTY_NORMAL);
|
|
}
|
|
}
|
|
tty_flip_buffer_push(tty);
|
|
tty_kref_put(tty);
|
|
}
|
|
EXPORT_SYMBOL_GPL(usb_serial_generic_process_read_urb);
|
|
|
|
void usb_serial_generic_read_bulk_callback(struct urb *urb)
|
|
{
|
|
struct usb_serial_port *port = urb->context;
|
|
unsigned char *data = urb->transfer_buffer;
|
|
int status = urb->status;
|
|
unsigned long flags;
|
|
|
|
dbg("%s - port %d", __func__, port->number);
|
|
|
|
if (unlikely(status != 0)) {
|
|
dbg("%s - nonzero read bulk status received: %d",
|
|
__func__, status);
|
|
return;
|
|
}
|
|
|
|
usb_serial_debug_data(debug, &port->dev, __func__,
|
|
urb->actual_length, data);
|
|
port->serial->type->process_read_urb(urb);
|
|
|
|
/* Throttle the device if requested by tty */
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
port->throttled = port->throttle_req;
|
|
if (!port->throttled) {
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
usb_serial_generic_submit_read_urb(port, GFP_ATOMIC);
|
|
} else
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
|
|
|
|
void usb_serial_generic_write_bulk_callback(struct urb *urb)
|
|
{
|
|
unsigned long flags;
|
|
struct usb_serial_port *port = urb->context;
|
|
int status = urb->status;
|
|
int i;
|
|
|
|
dbg("%s - port %d", __func__, port->number);
|
|
|
|
for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
|
|
if (port->write_urbs[i] == urb)
|
|
break;
|
|
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
port->tx_bytes -= urb->transfer_buffer_length;
|
|
set_bit(i, &port->write_urbs_free);
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
|
|
if (status) {
|
|
dbg("%s - non-zero urb status: %d", __func__, status);
|
|
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
kfifo_reset_out(&port->write_fifo);
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
} else {
|
|
usb_serial_generic_write_start(port);
|
|
}
|
|
|
|
usb_serial_port_softint(port);
|
|
}
|
|
EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
|
|
|
|
void usb_serial_generic_throttle(struct tty_struct *tty)
|
|
{
|
|
struct usb_serial_port *port = tty->driver_data;
|
|
unsigned long flags;
|
|
|
|
dbg("%s - port %d", __func__, port->number);
|
|
|
|
/* Set the throttle request flag. It will be picked up
|
|
* by usb_serial_generic_read_bulk_callback(). */
|
|
spin_lock_irqsave(&port->lock, flags);
|
|
port->throttle_req = 1;
|
|
spin_unlock_irqrestore(&port->lock, flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(usb_serial_generic_throttle);
|
|
|
|
void usb_serial_generic_unthrottle(struct tty_struct *tty)
|
|
{
|
|
struct usb_serial_port *port = tty->driver_data;
|
|
int was_throttled;
|
|
|
|
dbg("%s - port %d", __func__, port->number);
|
|
|
|
/* Clear the throttle flags */
|
|
spin_lock_irq(&port->lock);
|
|
was_throttled = port->throttled;
|
|
port->throttled = port->throttle_req = 0;
|
|
spin_unlock_irq(&port->lock);
|
|
|
|
if (was_throttled)
|
|
usb_serial_generic_submit_read_urb(port, GFP_KERNEL);
|
|
}
|
|
EXPORT_SYMBOL_GPL(usb_serial_generic_unthrottle);
|
|
|
|
#ifdef CONFIG_MAGIC_SYSRQ
|
|
int usb_serial_handle_sysrq_char(struct tty_struct *tty,
|
|
struct usb_serial_port *port, unsigned int ch)
|
|
{
|
|
if (port->sysrq && port->port.console) {
|
|
if (ch && time_before(jiffies, port->sysrq)) {
|
|
handle_sysrq(ch, tty);
|
|
port->sysrq = 0;
|
|
return 1;
|
|
}
|
|
port->sysrq = 0;
|
|
}
|
|
return 0;
|
|
}
|
|
#else
|
|
int usb_serial_handle_sysrq_char(struct tty_struct *tty,
|
|
struct usb_serial_port *port, unsigned int ch)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char);
|
|
|
|
int usb_serial_handle_break(struct usb_serial_port *port)
|
|
{
|
|
if (!port->sysrq) {
|
|
port->sysrq = jiffies + HZ*5;
|
|
return 1;
|
|
}
|
|
port->sysrq = 0;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(usb_serial_handle_break);
|
|
|
|
int usb_serial_generic_resume(struct usb_serial *serial)
|
|
{
|
|
struct usb_serial_port *port;
|
|
int i, c = 0, r;
|
|
|
|
for (i = 0; i < serial->num_ports; i++) {
|
|
port = serial->port[i];
|
|
if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags))
|
|
continue;
|
|
|
|
if (port->read_urb) {
|
|
r = usb_submit_urb(port->read_urb, GFP_NOIO);
|
|
if (r < 0)
|
|
c++;
|
|
}
|
|
|
|
if (port->bulk_out_size) {
|
|
r = usb_serial_generic_write_start(port);
|
|
if (r < 0)
|
|
c++;
|
|
}
|
|
}
|
|
|
|
return c ? -EIO : 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(usb_serial_generic_resume);
|
|
|
|
void usb_serial_generic_disconnect(struct usb_serial *serial)
|
|
{
|
|
int i;
|
|
|
|
dbg("%s", __func__);
|
|
|
|
/* stop reads and writes on all ports */
|
|
for (i = 0; i < serial->num_ports; ++i)
|
|
generic_cleanup(serial->port[i]);
|
|
}
|
|
|
|
void usb_serial_generic_release(struct usb_serial *serial)
|
|
{
|
|
dbg("%s", __func__);
|
|
}
|