From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Thumshirn Subject: Re: [PATCH] tty: serial: men_z135_uart: Wakeup UART after transmitting Date: Fri, 13 Jun 2014 08:21:38 +0200 Message-ID: <20140613062137.GA15556@jtlinux> References: <1402639566-15493-1-git-send-email-johannes.thumshirn@men.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Received: from mail1.bemta5.messagelabs.com ([195.245.231.149]:31284 "EHLO mail1.bemta5.messagelabs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751534AbaFMGU0 (ORCPT ); Fri, 13 Jun 2014 02:20:26 -0400 Content-Disposition: inline In-Reply-To: <1402639566-15493-1-git-send-email-johannes.thumshirn@men.de> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Greg Kroah-Hartman , Jiri Slaby Cc: linux-serial@vger.kernel.org, Jun Shih , Johannes Thumshirn On Fri, Jun 13, 2014 at 08:06:06AM +0200, Johannes Thumshirn wrote: > From: Johannes Thumshirn > > Call uart_write_wakeup() after writing the hardware FIFO and updateing the FIFO > pointers. > > This fixes high latency and jitter on PPP over Serial links. > > Reported-by: Jun Shih > Tested-by: Jun Shih > Signed-off-by: Johannes Thumshirn > --- > drivers/tty/serial/men_z135_uart.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/tty/serial/men_z135_uart.c b/drivers/tty/serial/men_z135_uart.c > index c9d1854..30e9e60 100644 > --- a/drivers/tty/serial/men_z135_uart.c > +++ b/drivers/tty/serial/men_z135_uart.c > @@ -308,9 +308,6 @@ static void men_z135_handle_tx(struct men_z135_port *uart) > if (port->x_char) > goto out; > > - if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) > - uart_write_wakeup(port); > - > /* calculate bytes to copy */ > qlen = uart_circ_chars_pending(xmit); > if (qlen <= 0) > @@ -357,6 +354,9 @@ static void men_z135_handle_tx(struct men_z135_port *uart) > > port->icount.tx += n; > > + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) > + uart_write_wakeup(port); > + > irq_en: > if (!uart_circ_empty(xmit)) > men_z135_reg_set(uart, MEN_Z135_CONF_REG, MEN_Z135_IER_TXCIEN); > -- > 1.9.1 Somehow I managed to mistype my name in my gitconifg's email filed... Should I re-send the patch? Johannes