Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757081Ab3EHPwF (ORCPT ); Wed, 8 May 2013 11:52:05 -0400 Received: from mail-la0-f54.google.com ([209.85.215.54]:43376 "EHLO mail-la0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754558Ab3EHPwD (ORCPT ); Wed, 8 May 2013 11:52:03 -0400 From: Johan Hovold To: Greg Kroah-Hartman Cc: Peter Hurley , Stas Sergeev , Jarkko Huijts , Alan Cox , linux-usb@vger.kernel.org, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, Caylan Van Larson , "Rafael J. Wysocki" , Johan Hovold Subject: [PATCH v2 2/8] USB: serial: add generic wait_until_sent implementation Date: Wed, 8 May 2013 17:51:43 +0200 Message-Id: <1368028303-11923-1-git-send-email-jhovold@gmail.com> X-Mailer: git-send-email 1.8.2.1 In-Reply-To: <1367778753-22297-3-git-send-email-jhovold@gmail.com> References: <1367778753-22297-3-git-send-email-jhovold@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3933 Lines: 100 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 --- v2: make sure to handle B0 drivers/usb/serial/generic.c | 31 +++++++++++++++++++++++++++++++ drivers/usb/serial/usb-serial.c | 2 ++ include/linux/usb/serial.h | 3 +++ 3 files changed, 36 insertions(+) diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c index 297665f..ba45170 100644 --- a/drivers/usb/serial/generic.c +++ b/drivers/usb/serial/generic.c @@ -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) { diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c index 31d2768..60caf9c 100644 --- a/drivers/usb/serial/usb-serial.c +++ b/drivers/usb/serial/usb-serial.c @@ -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); diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h index afbb7ee..302ddf5 100644 --- a/include/linux/usb/serial.h +++ b/include/linux/usb/serial.h @@ -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); -- 1.8.2.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/