| From dcf0105039660e951dfea348d317043d17988dfc Mon Sep 17 00:00:00 2001 |
| From: Johan Hovold <jhovold@gmail.com> |
| Date: Wed, 8 May 2013 17:51:43 +0200 |
| Subject: USB: serial: add generic wait_until_sent implementation |
| |
| From: Johan Hovold <jhovold@gmail.com> |
| |
| commit dcf0105039660e951dfea348d317043d17988dfc upstream. |
| |
| 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: Johan Hovold <jhovold@gmail.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/usb/serial/generic.c | 31 +++++++++++++++++++++++++++++++ |
| drivers/usb/serial/usb-serial.c | 2 ++ |
| include/linux/usb/serial.h | 3 +++ |
| 3 files changed, 36 insertions(+) |
| |
| --- a/drivers/usb/serial/generic.c |
| +++ b/drivers/usb/serial/generic.c |
| @@ -264,6 +264,37 @@ int usb_serial_generic_chars_in_buffer(s |
| } |
| 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) |
| { |
| --- a/drivers/usb/serial/usb-serial.c |
| +++ b/drivers/usb/serial/usb-serial.c |
| @@ -1346,6 +1346,8 @@ static void fixup_generic(struct usb_ser |
| 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, disconnect); |
| --- a/include/linux/usb/serial.h |
| +++ b/include/linux/usb/serial.h |
| @@ -268,6 +268,7 @@ 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); |
| @@ -326,6 +327,8 @@ extern void usb_serial_generic_close(str |
| 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); |