From a00e7182308f41cac1aa071912ff7a16797dade9 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Tue, 14 Jan 2020 12:01:45 +0100 Subject: USB: serial: opticon: add chars_in_buffer() implementation Add a chars_in_buffer() implementation so that the tty layer will wait for outgoing buffered data to be drained when needed (e.g. on final close()). Reviewed-by: Greg Kroah-Hartman Signed-off-by: Johan Hovold --- drivers/usb/serial/opticon.c | 45 +++++++++++++++++++++++++++----------------- 1 file changed, 28 insertions(+), 17 deletions(-) (limited to 'drivers/usb/serial') diff --git a/drivers/usb/serial/opticon.c b/drivers/usb/serial/opticon.c index cb7aac9cd9e7..05ea21ed967c 100644 --- a/drivers/usb/serial/opticon.c +++ b/drivers/usb/serial/opticon.c @@ -41,6 +41,7 @@ struct opticon_private { bool rts; bool cts; int outstanding_urbs; + int outstanding_bytes; }; @@ -169,6 +170,7 @@ static void opticon_write_control_callback(struct urb *urb) spin_lock_irqsave(&priv->lock, flags); --priv->outstanding_urbs; + priv->outstanding_bytes -= urb->transfer_buffer_length; spin_unlock_irqrestore(&priv->lock, flags); usb_serial_port_softint(port); @@ -182,8 +184,8 @@ static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port, struct urb *urb; unsigned char *buffer; unsigned long flags; - int status; struct usb_ctrlrequest *dr; + int ret = -ENOMEM; spin_lock_irqsave(&priv->lock, flags); if (priv->outstanding_urbs > URB_UPPER_LIMIT) { @@ -192,19 +194,16 @@ static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port, return 0; } priv->outstanding_urbs++; + priv->outstanding_bytes += count; spin_unlock_irqrestore(&priv->lock, flags); buffer = kmalloc(count, GFP_ATOMIC); - if (!buffer) { - count = -ENOMEM; + if (!buffer) goto error_no_buffer; - } urb = usb_alloc_urb(0, GFP_ATOMIC); - if (!urb) { - count = -ENOMEM; + if (!urb) goto error_no_urb; - } memcpy(buffer, buf, count); @@ -213,10 +212,8 @@ static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port, /* The connected devices do not have a bulk write endpoint, * to transmit data to de barcode device the control endpoint is used */ dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC); - if (!dr) { - count = -ENOMEM; + if (!dr) goto error_no_dr; - } dr->bRequestType = USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT; dr->bRequest = 0x01; @@ -230,12 +227,9 @@ static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port, opticon_write_control_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 endpoint) failed status = %d\n", - __func__, status); - count = status; + ret = usb_submit_urb(urb, GFP_ATOMIC); + if (ret) { + dev_err(&port->dev, "failed to submit write urb: %d\n", ret); goto error; } @@ -253,8 +247,10 @@ error_no_urb: error_no_buffer: spin_lock_irqsave(&priv->lock, flags); --priv->outstanding_urbs; + priv->outstanding_bytes -= count; spin_unlock_irqrestore(&priv->lock, flags); - return count; + + return ret; } static int opticon_write_room(struct tty_struct *tty) @@ -279,6 +275,20 @@ static int opticon_write_room(struct tty_struct *tty) return 2048; } +static int opticon_chars_in_buffer(struct tty_struct *tty) +{ + struct usb_serial_port *port = tty->driver_data; + struct opticon_private *priv = usb_get_serial_port_data(port); + unsigned long flags; + int count; + + spin_lock_irqsave(&priv->lock, flags); + count = priv->outstanding_bytes; + spin_unlock_irqrestore(&priv->lock, flags); + + return count; +} + static int opticon_tiocmget(struct tty_struct *tty) { struct usb_serial_port *port = tty->driver_data; @@ -383,6 +393,7 @@ static struct usb_serial_driver opticon_device = { .open = opticon_open, .write = opticon_write, .write_room = opticon_write_room, + .chars_in_buffer = opticon_chars_in_buffer, .throttle = usb_serial_generic_throttle, .unthrottle = usb_serial_generic_unthrottle, .get_serial = get_serial_info, -- cgit v1.2.3