From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752872AbaIKAEd (ORCPT ); Wed, 10 Sep 2014 20:04:33 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:59074 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751658AbaIKAEc (ORCPT ); Wed, 10 Sep 2014 20:04:32 -0400 Date: Wed, 10 Sep 2014 17:03:43 -0700 From: Greg Kroah-Hartman To: Peter Hurley Cc: Jiri Slaby , One Thousand Gnomes , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC] tty: Always allow tcflow(TCOON) to unwedge terminal Message-ID: <20140911000343.GA5328@kroah.com> References: <1410384499-4982-1-git-send-email-peter@hurleysoftware.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1410384499-4982-1-git-send-email-peter@hurleysoftware.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 10, 2014 at 05:28:19PM -0400, Peter Hurley wrote: > This patch changes user-space behavior (for the better) but I'm not sure > that it's consequence-free. Also, it might not be enough to unwedge the > terminal if the driver got its own flow control state mangled. > > Thoughts? > > --- >% --- > Subject: [RFC] tty: Always allow tcflow(TCOON) to unwedge terminal > > If terminal flow has been stopped, the terminal can be unwedged > by: > tcflow(fd, TCOOFF); > tcflow(fd, TCOON); > This works because tcflow(TCOOFF) ensures that ->flow_stopped is set, > which allows tcflow(TCOON) to override the terminal flow state in > __start_tty(). > > Instead, allow unwedging with only: > tcflow(fd, TCOON); > by disregarding the existing ->flow_stopped state. I don't see the benifit here, what are you trying to solve? Sending one extra tcflow command? thanks, greg k-h