Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754878Ab3IMTMl (ORCPT ); Fri, 13 Sep 2013 15:12:41 -0400 Received: from mail-la0-f48.google.com ([209.85.215.48]:62487 "EHLO mail-la0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752999Ab3IMTMi (ORCPT ); Fri, 13 Sep 2013 15:12:38 -0400 Message-ID: <523363A9.6080102@cogentembedded.com> Date: Fri, 13 Sep 2013 23:12:41 +0400 From: Sergei Shtylyov Organization: Cogent Embedded User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130801 Thunderbird/17.0.8 MIME-Version: 1.0 To: Paul Chavent CC: linux-usb@vger.kernel.org, gregkh@linuxfoundation.org, jhovold@gmail.com, fschaefer.oss@googlemail.com, jslaby@suse.cz, max@suse.de, giometti@enneenne.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/3] USB : serial : invoke dcd_change ldisc's handler. References: <1379086513-2434-1-git-send-email-paul.chavent@onera.fr> <1379086513-2434-3-git-send-email-paul.chavent@onera.fr> In-Reply-To: <1379086513-2434-3-git-send-email-paul.chavent@onera.fr> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1911 Lines: 60 Hello. On 09/13/2013 07:35 PM, Paul Chavent wrote: > Signed-off-by: Paul Chavent > --- > Documentation/pps/pps.txt | 15 +++++++++++++++ > drivers/usb/serial/generic.c | 9 +++++++++ > 2 files changed, 24 insertions(+) > diff --git a/Documentation/pps/pps.txt b/Documentation/pps/pps.txt > index d35dcdd..67b9a94 100644 > --- a/Documentation/pps/pps.txt > +++ b/Documentation/pps/pps.txt > @@ -66,6 +66,21 @@ In LinuxPPS the PPS sources are simply char devices usually mapped > into files /dev/pps0, /dev/pps1, etc.. > > > +PPS with USB to serial devices > +------------------------------ > + > +It is possible to grab the PPS from an USB to serial device. However, > +you should take into account the latencies and jitter introduced by > +the USB stack. Users has reported clock instability around +-1ms when > +synchronized with PPS through USB. This isn't suited for time server > +synchronisation. Thunderbird spellchecker underlines this word -- "synchronization" is probably better. [...] > diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c > index 1f31e6b..877d6e0 100644 > --- a/drivers/usb/serial/generic.c > +++ b/drivers/usb/serial/generic.c > @@ -568,6 +568,15 @@ void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port, > { > struct tty_port *port = &usb_port->port; > > + if (tty) { > + struct tty_ldisc *ld = tty_ldisc_ref(tty); Insert an empty line after declaration as above -- keep the style consistent, please. > + if (ld) { > + if (ld->ops->dcd_change) > + ld->ops->dcd_change(tty, status); > + tty_ldisc_deref(ld); > + } > + } > + WBR, Sergei -- 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/