From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King Subject: Re: should RTS init in serial core be tied to CRTSCTS Date: Mon, 5 Mar 2007 17:56:04 +0000 Message-ID: <20070305175604.GB18548@flint.arm.linux.org.uk> References: <8bd0f97a0703011603m794e00f5x875eb68ad0db05de@mail.gmail.com> <20070304194632.GC30345@flint.arm.linux.org.uk> <8bd0f97a0703050909n18386114kd2c0b2a108591641@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from caramon.arm.linux.org.uk ([217.147.92.249]:3897 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752828AbXCER4N (ORCPT ); Mon, 5 Mar 2007 12:56:13 -0500 Content-Disposition: inline In-Reply-To: <8bd0f97a0703050909n18386114kd2c0b2a108591641@mail.gmail.com> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Mike Frysinger Cc: Linux Kernel Mailing List , linux-serial@vger.kernel.org, Robin Getz On Mon, Mar 05, 2007 at 12:09:20PM -0500, Mike Frysinger wrote: > On 3/4/07, Russell King wrote: > >On Thu, Mar 01, 2007 at 07:03:02PM -0500, Mike Frysinger wrote: > >> the console= bootcmd allows for controlling of the initial state of > >> flow control by adding/omitting the 'r' suffix ... > > > >The console command *only* sets the state for the kernel's use of one > >serial port. It does not affect any other serial port, so tying > >random RTS behaviours into that command line option is absolutely > >silly. > > true ... so ignoring the original motivation for change i posted, is > it really correct for the serial core to be forcing TIOCM_RTS at uart > startup even though the uart doesnt have CTSRTS flow control enabled ? > in other words, my change is agnostic of the console, and is done for > all uarts ... it should prob have a similar change in uart_shutdown() > though ... No idea - it's something that Linux has always done. Neither do I have any idea if changing it will break anyones setup. However, since I don't maintain serial anymore, I'm not about to start playing about with this trying to find out. Feel free to submit a patch to akpm to leave RTS alone when CRTSCTS is not set. I'd recommend that it sits in -mm for about 6 months to really get an idea if it breaks anything. -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: