From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Edwards Subject: Re: Add hardware handshaking to pseudo-tty and USB serial gadget Date: Fri, 22 Mar 2013 14:22:39 +0000 (UTC) Message-ID: References: <5D7CD300-386D-4AA1-B48A-0051D17C1F1F@beamcommunications.com> <1363904564.4488.47.camel@thor.lan> Return-path: Received: from plane.gmane.org ([80.91.229.3]:59451 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932928Ab3CVOWz (ORCPT ); Fri, 22 Mar 2013 10:22:55 -0400 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1UJ2sG-0005Wq-JY for linux-serial@vger.kernel.org; Fri, 22 Mar 2013 15:23:16 +0100 Received: from dsl.comtrol.com ([64.122.56.22]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 22 Mar 2013 15:23:16 +0100 Received: from grant.b.edwards by dsl.comtrol.com with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 22 Mar 2013 15:23:16 +0100 Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: linux-serial@vger.kernel.org On 2013-03-21, Peter Hurley wrote: > On Thu, 2013-03-21 at 20:38 +0000, Grant Edwards wrote: >> On 2013-03-21, Craig McQueen wrote: >> > It sounds as though people have done pseudo-ttys with HW handshaking >> > support--eg tty0tty project. However I'd rather implement this >> > function in the kernel pseudo-terminal driver itself. Is there any >> > reason not to do that? >> >> No reason other than you and I are the only two people who care about >> it. :) > > Assuming you're leaning toward an in-kernel solution, why not just > implement a new tty driver that behaves like a local serial port? I've been thinking about trying to do that except making it a serial_core driver on the slave side rather than a tty driver. I just converted a tty driver to the serial-core API and the code-size dropped by almost 70% (hopefully the undiscovered bug count dropped as well). I hadn't decided what to do for a master-side API. I'd probably abandon the standard tty API altogether and do something from scratch as a plain char device driver with custom ioctl calls. -- Grant Edwards grant.b.edwards Yow! A dwarf is passing out at somewhere in Detroit! gmail.com