From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751263AbaGJXY7 (ORCPT ); Thu, 10 Jul 2014 19:24:59 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:60495 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750919AbaGJXY6 (ORCPT ); Thu, 10 Jul 2014 19:24:58 -0400 Date: Thu, 10 Jul 2014 16:29:24 -0700 From: Greg KH To: David Miller Cc: peter@hurleysoftware.com, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, sethb@digi.com, aaro.koskinen@iki.fi, sam@ravnborg.org, tsbogend@alpha.franken.de Subject: Re: [PATCH 0/2] fixes for empty tx buffer breakage Message-ID: <20140710232924.GA9954@kroah.com> References: <20140609205917.GA913@drone.musicnaut.iki.fi> <1404660593-12172-1-git-send-email-peter@hurleysoftware.com> <20140710231432.GA9423@kroah.com> <20140710.161205.2079073830695357277.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140710.161205.2079073830695357277.davem@davemloft.net> 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 Thu, Jul 10, 2014 at 04:12:05PM -0700, David Miller wrote: > From: Greg Kroah-Hartman > Date: Thu, 10 Jul 2014 16:14:32 -0700 > > > On Sun, Jul 06, 2014 at 11:29:51AM -0400, Peter Hurley wrote: > >> Cc: Seth Bollinger > >> Cc: Aaro Koskinen > >> Cc: Sam Ravnborg > >> Cc: "David S. Miller" > >> Cc: Thomas Bogendoerfer > >> > >> Greg, > >> > >> I completed the audit of serial drivers after reports that > >> several Sun serial drivers were broken by > >> commit 717f3bbab3c7628736ef738fdbf3d9a28578c26c, > >> 'serial_core: Fix conditional start_tx on ring buffer not empty'. > >> > >> I apologize for not submitting this sooner. The delay was due to > >> an ongoing analysis of serial flow control prompted by Sam Ravnborg's > >> question: > >> > >> On 06/10/2014 03:24 PM, Sam Ravnborg wrote: > >> > I also noticed the typical pattern is: > >> > > >> > if (uart_circ_empty(xmit) || uart_tx_stopped(port)) > >> > > >> > Should you use this pattern also in sunsab.c? > >> > >> Unfortunately, that analysis revealed that tx flow control is > >> largely SMP-unsafe, and it's fairly easy to corrupt the hardware > >> state wrt. the tty flow control state. > >> > >> I'm still working on the solutions to that; they're too > >> extensive to submit for 3.16 anyway. > > > > So these should go into 3.16-final? Or 3.17? > > Definitely 3.16, this regression is several releases old. Ok, will queue it up, thanks. gre gk-h