From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vx0-f171.google.com (mail-vx0-f171.google.com [209.85.220.171]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 9B783200BFD for ; Wed, 14 Mar 2012 20:33:37 -0700 (PDT) Received: by vcbfl15 with SMTP id fl15so5499233vcb.16 for ; Wed, 14 Mar 2012 20:33:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; bh=mLYPJPwVmbmO0DpOp4Fa/SeOPxBbGSVmj1q+1h68X1I=; b=fcLPGFRP2yhoPqytv2I6BtuwcOXwaNzVAm4P8tQ3QwWvK54OVzZuocInHyn9Km6/Ie B6j34nojhHXSgUvbfGYbvdKNhY3Aw/NhveI9FVBWVySJ3bN8IonBZJrPwCsJIiCXU9zD KDgk3AK09xWcAuCyZsOUeEKcBMTY68LL94jgnSvEMeY4qqsp+ABj0EuW4y1RoQ6ezIJI VHczN0JCP569FLD1IMcLoxt3vPFIWcuZNPVRI4exbK+1JyBDAEZsEZ8jpyHXvJ5NqNKc u2QhPNaF/g/KdJTDy3ZsakrGgqG3lHKqprKokkucDT6JQGKAilwVQpx5qbJfTmWUyXUs 2rTg== MIME-Version: 1.0 Received: by 10.52.34.175 with SMTP id a15mr3629542vdj.18.1331782416327; Wed, 14 Mar 2012 20:33:36 -0700 (PDT) Received: by 10.220.140.132 with HTTP; Wed, 14 Mar 2012 20:33:36 -0700 (PDT) In-Reply-To: <20120314184258.GA30210@thyrsus.com> References: <20120314104920.697EA40617@snark.thyrsus.com> <20120314184258.GA30210@thyrsus.com> Date: Wed, 14 Mar 2012 22:33:36 -0500 Message-ID: From: Patrick Maupin To: esr@thyrsus.com Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: thumbgps-devel@lists.bufferbloat.net Subject: Re: [Thumbgps-devel] USB handshake signals and Linux X-BeenThere: thumbgps-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 15 Mar 2012 03:33:37 -0000 On Wed, Mar 14, 2012 at 1:42 PM, Eric S. Raymond wrote: > I found a couple of hits on the search "PL2303 latency timer" that > implies it has one too. =A0But I doubt the value of the latency timer > will be relevant for handshake-line notifications; see below. The latency timer on the FTDI parts can be dropped to a millisecond. If we find a USB dongle that has a USB converter with similar capabilities and a GPS chipset that has rock-solid first-character timing, we might avoid needing the RS232 handshake altogether. (We might need to drop the baud rate to avoid losing data, but that's not a huge deal.)