From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 19338 invoked by alias); 5 Apr 2011 16:10:24 -0000 Received: (qmail 19329 invoked by uid 22791); 5 Apr 2011 16:10:23 -0000 X-SWARE-Spam-Status: No, hits=-1.9 required=5.0 tests=AWL,BAYES_00,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from mail.codesourcery.com (HELO mail.codesourcery.com) (38.113.113.100) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 05 Apr 2011 16:10:17 +0000 Received: (qmail 31787 invoked from network); 5 Apr 2011 16:10:16 -0000 Received: from unknown (HELO scottsdale.localnet) (pedro@127.0.0.2) by mail.codesourcery.com with ESMTPA; 5 Apr 2011 16:10:16 -0000 From: Pedro Alves To: gdb-patches@sourceware.org Subject: Re: [PATCH] remote target interrupt before ack Date: Tue, 05 Apr 2011 16:10:00 -0000 User-Agent: KMail/1.13.5 (Linux/2.6.35-28-generic; KDE/4.6.1; x86_64; ; ) Cc: Michael Walle References: <201104042200.15473.michael@walle.cc> <201104042121.22036.pedro@codesourcery.com> <201104042238.32058.michael@walle.cc> In-Reply-To: <201104042238.32058.michael@walle.cc> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201104051710.10938.pedro@codesourcery.com> X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2011-04/txt/msg00073.txt.bz2 On Monday 04 April 2011 21:38:32, Michael Walle wrote: > Am Montag 04 April 2011, 22:21:21 schrieb Pedro Alves: > > On Monday 04 April 2011 21:00:15, Michael Walle wrote: > > > the following patch puts the sending of the interrupt/break sequence > > > before the proforma ACK. This guarantees the ACK won't be delivered to > > > an application on the remote side. > > > > > Can you explain what the latter sentence means a bit better? > > > Oh, i forgot to mention that this bug affects serial lines which are shared > with the GDB stub. Assume the remote needs a BREAK to start its gdb stub. If > you send the '+' before the BREAK it will be delivered to the actual > application running on the device (and of course listening on the serial > port). [If there happens to be some echo service things will even go worse, > because the echoed '+' will be interpreted by GDB as an ACK to the first sent > packet.] Okay, makes sense. I figured it was something like that, but doesn't hurt to be explicit so we don't have to guess, and for the benefit of the archives. Patch is okay, thanks. -- Pedro Alves