USB: generic usb serial to new buffering scheme (1abdeeb1) · Commits · 戴 / test

drivers/usb/serial/generic.c

+34 −35

Original line number	Diff line number	Diff line
		@@ -281,45 +281,54 @@ int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port)
		return (chars);
		}

		/* Push data to tty layer and resubmit the bulk read URB */
		static void flush_and_resubmit_read_urb (struct usb_serial_port *port)

		static void resubmit_read_urb(struct usb_serial_port *port, gfp_t mem_flags)
		{
		struct usb_serial *serial = port->serial;
		struct urb *urb = port->read_urb;
		struct tty_struct *tty = port->tty;
		struct usb_serial *serial = port->serial;
		int result;

		/* Push data to tty */
		if (tty && urb->actual_length) {
		tty_buffer_request_room(tty, urb->actual_length);
		tty_insert_flip_string(tty, urb->transfer_buffer, urb->actual_length);
		tty_flip_buffer_push(tty); /* is this allowed from an URB callback ? */
		}

		/* Continue reading from device */
		usb_fill_bulk_urb (port->read_urb, serial->dev,
		usb_fill_bulk_urb (urb, serial->dev,
		usb_rcvbulkpipe (serial->dev,
		port->bulk_in_endpointAddress),
		port->read_urb->transfer_buffer,
		port->read_urb->transfer_buffer_length,
		urb->transfer_buffer,
		urb->transfer_buffer_length,
		((serial->type->read_bulk_callback) ?
		serial->type->read_bulk_callback :
		usb_serial_generic_read_bulk_callback), port);
		result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
		result = usb_submit_urb(urb, mem_flags);
		if (result)
		dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
		}

		/* Push data to tty layer and resubmit the bulk read URB */
		static void flush_and_resubmit_read_urb (struct usb_serial_port *port)
		{
		struct urb *urb = port->read_urb;
		struct tty_struct *tty = port->tty;
		int room;

		/* Push data to tty */
		if (tty && urb->actual_length) {
		room = tty_buffer_request_room(tty, urb->actual_length);
		if (room) {
		tty_insert_flip_string(tty, urb->transfer_buffer, room);
		tty_flip_buffer_push(tty); /* is this allowed from an URB callback ? */
		}
		}

		resubmit_read_urb(port, GFP_ATOMIC);
		}

		void usb_serial_generic_read_bulk_callback (struct urb *urb)
		{
		struct usb_serial_port port = (struct usb_serial_port )urb->context;
		unsigned char *data = urb->transfer_buffer;
		int is_throttled;
		unsigned long flags;

		dbg("%s - port %d", __FUNCTION__, port->number);

		if (urb->status) {
		if (unlikely(urb->status != 0)) {
		dbg("%s - nonzero read bulk status received: %d", __FUNCTION__, urb->status);
		return;
		}
		@@ -327,21 +336,11 @@ void usb_serial_generic_read_bulk_callback (struct urb *urb)
		usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);

		/* Throttle the device if requested by tty */
		if (urb->actual_length) {
		spin_lock_irqsave(&port->lock, flags);
		is_throttled = port->throttled = port->throttle_req;
		spin_unlock_irqrestore(&port->lock, flags);
		if (is_throttled) {
		/* Let the received data linger in the read URB;
		* usb_serial_generic_unthrottle() will pick it
		* up later. */
		dbg("%s - throttling device", __FUNCTION__);
		return;
		}
		}

		spin_lock(&port->lock);
		if (!(port->throttled = port->throttle_req))
		/* Handle data and continue reading from device */
		flush_and_resubmit_read_urb(port);
		spin_unlock(&port->lock);
		}
		EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);

		@@ -388,8 +387,8 @@ void usb_serial_generic_unthrottle (struct usb_serial_port *port)
		spin_unlock_irqrestore(&port->lock, flags);

		if (was_throttled) {
		/* Handle pending data and resume reading from device */
		flush_and_resubmit_read_urb(port);
		/* Resume reading from device */
		resubmit_read_urb(port, GFP_KERNEL);
		}
		}

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