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USB: ftdi_sio: re-implement read processing
- Re-structure read processing. - Kill obsolete work queue and always push to tty in completion handler. - Use tty_insert_flip_string instead of per character push when possible. - Fix stalled-read regression in 2.6.31 by using urb status to determine when port is closed rather than port count. - Fix race with open/close by checking ASYNCB_INITIALIZED in unthrottle. - Kill private rx_flag and lock and use throttle flags in usb_serial_port instead. Signed-off-by: Johan Hovold <jhovold@gmail.com> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Johan Hovold
Greg Kroah-Hartman
parent
e63e278b4d
commit
cc01f17d5c
@ -76,12 +76,7 @@ struct ftdi_private {
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unsigned long last_dtr_rts; /* saved modem control outputs */
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wait_queue_head_t delta_msr_wait; /* Used for TIOCMIWAIT */
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char prev_status, diff_status; /* Used for TIOCMIWAIT */
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__u8 rx_flags; /* receive state flags (throttling) */
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spinlock_t rx_lock; /* spinlock for receive state */
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struct delayed_work rx_work;
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struct usb_serial_port *port;
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int rx_processed;
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__u16 interface; /* FT2232C, FT2232H or FT4232H port interface
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(0 for FT232/245) */
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@ -736,10 +731,6 @@ static const char *ftdi_chip_name[] = {
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/* Constants for read urb and write urb */
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#define BUFSZ 512
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/* rx_flags */
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#define THROTTLED 0x01
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#define ACTUALLY_THROTTLED 0x02
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/* Used for TIOCMIWAIT */
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#define FTDI_STATUS_B0_MASK (FTDI_RS0_CTS | FTDI_RS0_DSR | FTDI_RS0_RI | FTDI_RS0_RLSD)
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#define FTDI_STATUS_B1_MASK (FTDI_RS_BI)
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@ -762,7 +753,7 @@ static int ftdi_write_room(struct tty_struct *tty);
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static int ftdi_chars_in_buffer(struct tty_struct *tty);
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static void ftdi_write_bulk_callback(struct urb *urb);
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static void ftdi_read_bulk_callback(struct urb *urb);
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static void ftdi_process_read(struct work_struct *work);
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static void ftdi_process_read(struct usb_serial_port *port);
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static void ftdi_set_termios(struct tty_struct *tty,
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struct usb_serial_port *port, struct ktermios *old);
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static int ftdi_tiocmget(struct tty_struct *tty, struct file *file);
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@ -1525,7 +1516,6 @@ static int ftdi_sio_port_probe(struct usb_serial_port *port)
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}
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kref_init(&priv->kref);
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spin_lock_init(&priv->rx_lock);
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spin_lock_init(&priv->tx_lock);
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init_waitqueue_head(&priv->delta_msr_wait);
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/* This will push the characters through immediately rather
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@ -1547,7 +1537,6 @@ static int ftdi_sio_port_probe(struct usb_serial_port *port)
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port->read_urb->transfer_buffer_length = BUFSZ;
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}
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INIT_DELAYED_WORK(&priv->rx_work, ftdi_process_read);
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priv->port = port;
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/* Free port's existing write urb and transfer buffer. */
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@ -1684,6 +1673,26 @@ static int ftdi_sio_port_remove(struct usb_serial_port *port)
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return 0;
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}
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static int ftdi_submit_read_urb(struct usb_serial_port *port, gfp_t mem_flags)
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{
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struct urb *urb = port->read_urb;
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struct usb_serial *serial = port->serial;
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int result;
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usb_fill_bulk_urb(urb, serial->dev,
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usb_rcvbulkpipe(serial->dev,
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port->bulk_in_endpointAddress),
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urb->transfer_buffer,
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urb->transfer_buffer_length,
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ftdi_read_bulk_callback, port);
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result = usb_submit_urb(urb, mem_flags);
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if (result)
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dev_err(&port->dev,
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"%s - failed submitting read urb, error %d\n",
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__func__, result);
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return result;
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}
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static int ftdi_open(struct tty_struct *tty, struct usb_serial_port *port)
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{ /* ftdi_open */
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struct usb_device *dev = port->serial->dev;
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@ -1717,23 +1726,14 @@ static int ftdi_open(struct tty_struct *tty, struct usb_serial_port *port)
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ftdi_set_termios(tty, port, tty->termios);
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/* Not throttled */
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spin_lock_irqsave(&priv->rx_lock, flags);
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priv->rx_flags &= ~(THROTTLED | ACTUALLY_THROTTLED);
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spin_unlock_irqrestore(&priv->rx_lock, flags);
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spin_lock_irqsave(&port->lock, flags);
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port->throttled = 0;
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port->throttle_req = 0;
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spin_unlock_irqrestore(&port->lock, flags);
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/* Start reading from the device */
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priv->rx_processed = 0;
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usb_fill_bulk_urb(port->read_urb, dev,
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usb_rcvbulkpipe(dev, port->bulk_in_endpointAddress),
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port->read_urb->transfer_buffer,
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port->read_urb->transfer_buffer_length,
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ftdi_read_bulk_callback, port);
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result = usb_submit_urb(port->read_urb, GFP_KERNEL);
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if (result)
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dev_err(&port->dev,
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"%s - failed submitting read urb, error %d\n",
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__func__, result);
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else
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result = ftdi_submit_read_urb(port, GFP_KERNEL);
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if (!result)
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kref_get(&priv->kref);
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return result;
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@ -1779,10 +1779,6 @@ static void ftdi_close(struct usb_serial_port *port)
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dbg("%s", __func__);
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/* cancel any scheduled reading */
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cancel_delayed_work_sync(&priv->rx_work);
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/* shutdown our bulk read */
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usb_kill_urb(port->read_urb);
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kref_put(&priv->kref, ftdi_sio_priv_release);
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@ -2005,236 +2001,121 @@ static int ftdi_chars_in_buffer(struct tty_struct *tty)
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return buffered;
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}
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static void ftdi_read_bulk_callback(struct urb *urb)
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static int ftdi_process_packet(struct tty_struct *tty,
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struct usb_serial_port *port, struct ftdi_private *priv,
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char *packet, int len)
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{
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struct usb_serial_port *port = urb->context;
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struct ftdi_private *priv;
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int status = urb->status;
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int i;
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char status;
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char flag;
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char *ch;
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dbg("%s - port %d", __func__, port->number);
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if (port->port.count <= 0)
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return;
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if (status) {
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/* This will happen at close every time so it is a dbg not an
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err */
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dbg("(this is ok on close) nonzero read bulk status received: %d", status);
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goto out;
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if (len < 2) {
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dbg("malformed packet");
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return 0;
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}
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priv = usb_get_serial_port_data(port);
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ftdi_process_read(&priv->rx_work.work);
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} /* ftdi_read_bulk_callback */
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/* Compare new line status to the old one, signal if different/
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N.B. packet may be processed more than once, but differences
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are only processed once. */
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status = packet[0] & FTDI_STATUS_B0_MASK;
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if (status != priv->prev_status) {
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priv->diff_status |= status ^ priv->prev_status;
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wake_up_interruptible(&priv->delta_msr_wait);
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priv->prev_status = status;
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}
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/*
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* Although the device uses a bitmask and hence can have multiple
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* errors on a packet - the order here sets the priority the error is
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* returned to the tty layer.
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*/
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flag = TTY_NORMAL;
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if (packet[1] & FTDI_RS_OE) {
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flag = TTY_OVERRUN;
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dbg("OVERRRUN error");
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}
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if (packet[1] & FTDI_RS_BI) {
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flag = TTY_BREAK;
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dbg("BREAK received");
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usb_serial_handle_break(port);
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}
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if (packet[1] & FTDI_RS_PE) {
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flag = TTY_PARITY;
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dbg("PARITY error");
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}
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if (packet[1] & FTDI_RS_FE) {
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flag = TTY_FRAME;
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dbg("FRAMING error");
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}
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static void ftdi_process_read(struct work_struct *work)
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{ /* ftdi_process_read */
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struct ftdi_private *priv =
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container_of(work, struct ftdi_private, rx_work.work);
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struct usb_serial_port *port = priv->port;
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struct urb *urb;
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len -= 2;
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if (!len)
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return 0; /* status only */
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ch = packet + 2;
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if (!(port->console && port->sysrq) && flag == TTY_NORMAL)
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tty_insert_flip_string(tty, ch, len);
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else {
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for (i = 0; i < len; i++, ch++) {
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if (!usb_serial_handle_sysrq_char(tty, port, *ch))
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tty_insert_flip_char(tty, *ch, flag);
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}
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}
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return len;
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}
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static void ftdi_process_read(struct usb_serial_port *port)
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{
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struct urb *urb = port->read_urb;
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struct tty_struct *tty;
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char error_flag;
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unsigned char *data;
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struct ftdi_private *priv = usb_get_serial_port_data(port);
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char *data = (char *)urb->transfer_buffer;
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int i;
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int result;
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int need_flip;
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int packet_offset;
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int len;
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int count = 0;
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tty = tty_port_tty_get(&port->port);
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if (!tty)
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return;
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for (i = 0; i < urb->actual_length; i += priv->max_packet_size) {
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len = min_t(int, urb->actual_length - i, priv->max_packet_size);
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count += ftdi_process_packet(tty, port, priv, &data[i], len);
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}
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if (count)
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tty_flip_buffer_push(tty);
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tty_kref_put(tty);
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}
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static void ftdi_read_bulk_callback(struct urb *urb)
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{
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struct usb_serial_port *port = urb->context;
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unsigned long flags;
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dbg("%s - port %d", __func__, port->number);
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if (port->port.count <= 0)
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return;
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tty = tty_port_tty_get(&port->port);
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if (!tty) {
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dbg("%s - bad tty pointer - exiting", __func__);
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if (urb->status) {
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dbg("%s - nonzero read bulk status received: %d",
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__func__, urb->status);
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return;
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}
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priv = usb_get_serial_port_data(port);
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if (!priv) {
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dbg("%s - bad port private data pointer - exiting", __func__);
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goto out;
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}
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urb = port->read_urb;
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if (!urb) {
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dbg("%s - bad read_urb pointer - exiting", __func__);
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goto out;
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}
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data = urb->transfer_buffer;
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if (priv->rx_processed) {
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dbg("%s - already processed: %d bytes, %d remain", __func__,
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priv->rx_processed,
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urb->actual_length - priv->rx_processed);
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} else {
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/* The first two bytes of every read packet are status */
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if (urb->actual_length > 2)
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usb_serial_debug_data(debug, &port->dev, __func__,
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urb->actual_length, data);
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else
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dbg("Status only: %03oo %03oo", data[0], data[1]);
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}
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/* TO DO -- check for hung up line and handle appropriately: */
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/* send hangup */
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/* See acm.c - you do a tty_hangup - eg tty_hangup(tty) */
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/* if CD is dropped and the line is not CLOCAL then we should hangup */
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need_flip = 0;
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for (packet_offset = priv->rx_processed;
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packet_offset < urb->actual_length; packet_offset += priv->max_packet_size) {
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int length;
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/* Compare new line status to the old one, signal if different/
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N.B. packet may be processed more than once, but differences
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are only processed once. */
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char new_status = data[packet_offset + 0] &
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FTDI_STATUS_B0_MASK;
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if (new_status != priv->prev_status) {
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priv->diff_status |=
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new_status ^ priv->prev_status;
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wake_up_interruptible(&priv->delta_msr_wait);
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priv->prev_status = new_status;
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}
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length = min_t(u32, priv->max_packet_size, urb->actual_length-packet_offset)-2;
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if (length < 0) {
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dev_err(&port->dev, "%s - bad packet length: %d\n",
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__func__, length+2);
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length = 0;
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}
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if (priv->rx_flags & THROTTLED) {
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dbg("%s - throttled", __func__);
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break;
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}
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if (tty_buffer_request_room(tty, length) < length) {
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/* break out & wait for throttling/unthrottling to
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happen */
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dbg("%s - receive room low", __func__);
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break;
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}
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/* Handle errors and break */
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error_flag = TTY_NORMAL;
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/* Although the device uses a bitmask and hence can have
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multiple errors on a packet - the order here sets the
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priority the error is returned to the tty layer */
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if (data[packet_offset+1] & FTDI_RS_OE) {
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error_flag = TTY_OVERRUN;
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dbg("OVERRRUN error");
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}
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if (data[packet_offset+1] & FTDI_RS_BI) {
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error_flag = TTY_BREAK;
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dbg("BREAK received");
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usb_serial_handle_break(port);
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}
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if (data[packet_offset+1] & FTDI_RS_PE) {
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error_flag = TTY_PARITY;
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dbg("PARITY error");
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}
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if (data[packet_offset+1] & FTDI_RS_FE) {
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error_flag = TTY_FRAME;
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dbg("FRAMING error");
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}
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if (length > 0) {
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for (i = 2; i < length+2; i++) {
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/* Note that the error flag is duplicated for
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every character received since we don't know
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which character it applied to */
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if (!usb_serial_handle_sysrq_char(tty, port,
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data[packet_offset + i]))
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tty_insert_flip_char(tty,
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data[packet_offset + i],
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error_flag);
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}
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need_flip = 1;
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}
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#ifdef NOT_CORRECT_BUT_KEEPING_IT_FOR_NOW
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/* if a parity error is detected you get status packets forever
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until a character is sent without a parity error.
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This doesn't work well since the application receives a
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never ending stream of bad data - even though new data
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hasn't been sent. Therefore I (bill) have taken this out.
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However - this might make sense for framing errors and so on
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so I am leaving the code in for now.
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*/
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else {
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if (error_flag != TTY_NORMAL) {
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dbg("error_flag is not normal");
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/* In this case it is just status - if that is
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an error send a bad character */
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if (tty->flip.count >= TTY_FLIPBUF_SIZE)
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tty_flip_buffer_push(tty);
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tty_insert_flip_char(tty, 0xff, error_flag);
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need_flip = 1;
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}
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}
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#endif
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} /* "for(packet_offset=0..." */
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/* Low latency */
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if (need_flip)
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tty_flip_buffer_push(tty);
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if (packet_offset < urb->actual_length) {
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/* not completely processed - record progress */
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priv->rx_processed = packet_offset;
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dbg("%s - incomplete, %d bytes processed, %d remain",
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__func__, packet_offset,
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urb->actual_length - packet_offset);
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/* check if we were throttled while processing */
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spin_lock_irqsave(&priv->rx_lock, flags);
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if (priv->rx_flags & THROTTLED) {
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priv->rx_flags |= ACTUALLY_THROTTLED;
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spin_unlock_irqrestore(&priv->rx_lock, flags);
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dbg("%s - deferring remainder until unthrottled",
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__func__);
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goto out;
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}
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spin_unlock_irqrestore(&priv->rx_lock, flags);
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/* if the port is closed stop trying to read */
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if (port->port.count > 0)
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/* delay processing of remainder */
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schedule_delayed_work(&priv->rx_work, 1);
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else
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dbg("%s - port is closed", __func__);
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goto out;
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}
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/* urb is completely processed */
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priv->rx_processed = 0;
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/* if the port is closed stop trying to read */
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if (port->port.count > 0) {
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/* Continue trying to always read */
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usb_fill_bulk_urb(port->read_urb, port->serial->dev,
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usb_rcvbulkpipe(port->serial->dev,
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port->bulk_in_endpointAddress),
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port->read_urb->transfer_buffer,
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port->read_urb->transfer_buffer_length,
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ftdi_read_bulk_callback, port);
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result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
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if (result)
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dev_err(&port->dev,
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"%s - failed resubmitting read urb, error %d\n",
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__func__, result);
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}
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out:
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tty_kref_put(tty);
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} /* ftdi_process_read */
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usb_serial_debug_data(debug, &port->dev, __func__,
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urb->actual_length, urb->transfer_buffer);
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ftdi_process_read(port);
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spin_lock_irqsave(&port->lock, flags);
|
||||
port->throttled = port->throttle_req;
|
||||
if (!port->throttled) {
|
||||
spin_unlock_irqrestore(&port->lock, flags);
|
||||
ftdi_submit_read_urb(port, GFP_ATOMIC);
|
||||
} else
|
||||
spin_unlock_irqrestore(&port->lock, flags);
|
||||
}
|
||||
|
||||
static void ftdi_break_ctl(struct tty_struct *tty, int break_state)
|
||||
{
|
||||
@ -2566,33 +2447,31 @@ static int ftdi_ioctl(struct tty_struct *tty, struct file *file,
|
||||
static void ftdi_throttle(struct tty_struct *tty)
|
||||
{
|
||||
struct usb_serial_port *port = tty->driver_data;
|
||||
struct ftdi_private *priv = usb_get_serial_port_data(port);
|
||||
unsigned long flags;
|
||||
|
||||
dbg("%s - port %d", __func__, port->number);
|
||||
|
||||
spin_lock_irqsave(&priv->rx_lock, flags);
|
||||
priv->rx_flags |= THROTTLED;
|
||||
spin_unlock_irqrestore(&priv->rx_lock, flags);
|
||||
spin_lock_irqsave(&port->lock, flags);
|
||||
port->throttle_req = 1;
|
||||
spin_unlock_irqrestore(&port->lock, flags);
|
||||
}
|
||||
|
||||
|
||||
static void ftdi_unthrottle(struct tty_struct *tty)
|
||||
void ftdi_unthrottle(struct tty_struct *tty)
|
||||
{
|
||||
struct usb_serial_port *port = tty->driver_data;
|
||||
struct ftdi_private *priv = usb_get_serial_port_data(port);
|
||||
int actually_throttled;
|
||||
int was_throttled;
|
||||
unsigned long flags;
|
||||
|
||||
dbg("%s - port %d", __func__, port->number);
|
||||
|
||||
spin_lock_irqsave(&priv->rx_lock, flags);
|
||||
actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
|
||||
priv->rx_flags &= ~(THROTTLED | ACTUALLY_THROTTLED);
|
||||
spin_unlock_irqrestore(&priv->rx_lock, flags);
|
||||
spin_lock_irqsave(&port->lock, flags);
|
||||
was_throttled = port->throttled;
|
||||
port->throttled = port->throttle_req = 0;
|
||||
spin_unlock_irqrestore(&port->lock, flags);
|
||||
|
||||
if (actually_throttled)
|
||||
schedule_delayed_work(&priv->rx_work, 0);
|
||||
/* Resubmit urb if throttled and open. */
|
||||
if (was_throttled && test_bit(ASYNCB_INITIALIZED, &port->port.flags))
|
||||
ftdi_submit_read_urb(port, GFP_KERNEL);
|
||||
}
|
||||
|
||||
static int __init ftdi_init(void)
|
||||
|
||||
Loading…
Reference in New Issue
Block a user