From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King Subject: Re: tcdrain / TCSBRK / wait_until_sent delay Date: Mon, 9 May 2005 09:59:03 +0100 Message-ID: <20050509095903.A5674@flint.arm.linux.org.uk> References: <200505071035.55508.andyparkins@gmail.com> <000a01c5546f$57d83f60$2e01a8c0@acksys.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from caramon.arm.linux.org.uk ([212.18.232.186]:39951 "EHLO caramon.arm.linux.org.uk") by vger.kernel.org with ESMTP id S261160AbVEII7M (ORCPT ); Mon, 9 May 2005 04:59:12 -0400 Content-Disposition: inline In-Reply-To: <000a01c5546f$57d83f60$2e01a8c0@acksys.fr>; from jp.tosoni@acksys.fr on Mon, May 09, 2005 at 10:16:03AM +0200 Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Tosoni Cc: 'Andy Parkins' , linux-serial@vger.kernel.org On Mon, May 09, 2005 at 10:16:03AM +0200, Tosoni wrote: > - Then Mr Russel King suggested to redesign a complete "line discipline" Please do me the reasonable curtesy of spelling my name correctly. > just to handle the missing RTS feature. I must note that such "line > discipline" would duplicate completely the existing default line discipline > except for the RTS_TOGGLE ioctl. Interestingly, I've reviewed our discussions back in December, and they aren't exactly how you recollect them to be. I gave you the historical position, and suggested both a possible way forward and someone else for you to talk to about this. It also appears that you continued to press for _your_ original implementation, justifying it against the historical position (both of which I'd already suggested weren't suitable.) Maybe I didn't explain clearly enough why your implementation wasn't suitable. Adding an IOCTL for RS485 RTS style vs conventional RTS style causes problems. Consider what happens when: 1. we get a third (and there are more than two) flow control styles. 2. the port is closed and something else opens it which wants standard flow control. (or even an overlapping open/close.) I have also suggested to a third party about adding a feature by which the flow control method could be changed between several different settings, preferably via the existing control implmentation - termios. This should resolve both of the above. Unfortunately, that also went by un-noticed and as such hasn't progressed. Therefore, there has been no progress on different flow control styles. -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core