Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit dcf01050 authored by Johan Hovold's avatar Johan Hovold Committed by Greg Kroah-Hartman
Browse files

USB: serial: add generic wait_until_sent implementation 



Add generic wait_until_sent implementation which polls for empty
hardware buffers using the new port-operation tx_empty.

The generic implementation will be used for all sub-drivers that
implement tx_empty but does not define wait_until_sent.

Signed-off-by: default avatarJohan Hovold <jhovold@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 0693196f

drivers/usb/serial/generic.c

+31 −0
Original line number Diff line number Diff line
@@ -253,6 +253,37 @@ int usb_serial_generic_chars_in_buffer(struct tty_struct *tty) 
}

EXPORT_SYMBOL_GPL(usb_serial_generic_chars_in_buffer);



void usb_serial_generic_wait_until_sent(struct tty_struct *tty, long timeout)

{

	struct usb_serial_port *port = tty->driver_data;

	unsigned int bps;

	unsigned long period;

	unsigned long expire;



	bps = tty_get_baud_rate(tty);

	if (!bps)

		bps = 9600;	/* B0 */

	/*

	 * Use a poll-period of roughly the time it takes to send one

	 * character or at least one jiffy.

	 */

	period = max_t(unsigned long, (10 * HZ / bps), 1);

	period = min_t(unsigned long, period, timeout);



	dev_dbg(&port->dev, "%s - timeout = %u ms, period = %u ms\n",

					__func__, jiffies_to_msecs(timeout),

					jiffies_to_msecs(period));

	expire = jiffies + timeout;

	while (!port->serial->type->tx_empty(port)) {

		schedule_timeout_interruptible(period);

		if (signal_pending(current))

			break;

		if (time_after(jiffies, expire))

			break;

	}

}

EXPORT_SYMBOL_GPL(usb_serial_generic_wait_until_sent);



static int usb_serial_generic_submit_read_urb(struct usb_serial_port *port,

						int index, gfp_t mem_flags)

{

drivers/usb/serial/usb-serial.c

+2 −0
Original line number Diff line number Diff line
@@ -1333,6 +1333,8 @@ static void usb_serial_operations_init(struct usb_serial_driver *device) 
	set_to_generic_if_null(device, close);

	set_to_generic_if_null(device, write_room);

	set_to_generic_if_null(device, chars_in_buffer);

	if (device->tx_empty)

		set_to_generic_if_null(device, wait_until_sent);

	set_to_generic_if_null(device, read_bulk_callback);

	set_to_generic_if_null(device, write_bulk_callback);

	set_to_generic_if_null(device, process_read_urb);

include/linux/usb/serial.h

+3 −0
Original line number Diff line number Diff line
@@ -269,6 +269,7 @@ struct usb_serial_driver { 
	void (*break_ctl)(struct tty_struct *tty, int break_state);

	int  (*chars_in_buffer)(struct tty_struct *tty);

	void (*wait_until_sent)(struct tty_struct *tty, long timeout);

	bool (*tx_empty)(struct usb_serial_port *port);

	void (*throttle)(struct tty_struct *tty);

	void (*unthrottle)(struct tty_struct *tty);

	int  (*tiocmget)(struct tty_struct *tty);
@@ -328,6 +329,8 @@ extern void usb_serial_generic_close(struct usb_serial_port *port); 
extern int usb_serial_generic_resume(struct usb_serial *serial);

extern int usb_serial_generic_write_room(struct tty_struct *tty);

extern int usb_serial_generic_chars_in_buffer(struct tty_struct *tty);

extern void usb_serial_generic_wait_until_sent(struct tty_struct *tty,

								long timeout);

extern void usb_serial_generic_read_bulk_callback(struct urb *urb);

extern void usb_serial_generic_write_bulk_callback(struct urb *urb);

extern void usb_serial_generic_throttle(struct tty_struct *tty);