Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756825Ab3FKUJn (ORCPT ); Tue, 11 Jun 2013 16:09:43 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:42014 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756640Ab3FKUEL (ORCPT ); Tue, 11 Jun 2013 16:04:11 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Johan Hovold Subject: [ 72/79] USB: serial: add generic wait_until_sent implementation Date: Tue, 11 Jun 2013 13:03:38 -0700 Message-Id: <20130611195325.501938037@linuxfoundation.org> X-Mailer: git-send-email 1.8.3.254.g5578ad7 In-Reply-To: <20130611195312.352656079@linuxfoundation.org> References: <20130611195312.352656079@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3761 Lines: 100 3.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold 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 Signed-off-by: Greg Kroah-Hartman --- 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); -- 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/