From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Slaby Subject: Re: [PATCH v2 1/6] TTY: serial, remove BTM from wait_until_sent Date: Wed, 10 Aug 2011 20:10:32 +0200 Message-ID: <4E42C998.1050208@gmail.com> References: <1310646915-3032-1-git-send-email-jslaby@suse.cz> <20110719003503.GA4138@amos.fritz.box> <4E3FE2D2.5020801@gmail.com> <20110810010933.GA4733@amos.fritz.box> <4E429907.6080000@gmail.com> <20110810180754.GB13832@bombe-desk.opditex> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-fx0-f46.google.com ([209.85.161.46]:45784 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750894Ab1HJSKi (ORCPT ); Wed, 10 Aug 2011 14:10:38 -0400 In-Reply-To: <20110810180754.GB13832@bombe-desk.opditex> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Jiri Slaby , gregkh@suse.de, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, Alan Cox , Arnd Bergmann On 08/10/2011 08:07 PM, Andreas Bombe wrote: > On Wed, Aug 10, 2011 at 04:43:19PM +0200, Jiri Slaby wrote: >> On 08/10/2011 03:09 AM, Andreas Bombe wrote: >>> I did my simple test on ttyS0 again: "stty -F /dev/ttyS0 crtscts" then >>> "echo >/dev/ttyS0". I attached the gzipped sysrq-t list in case you need >>> the complete output. This is just the process while it is trying to >>> close the device (bash's internal echo): >> >> Hmm, perhaps obvious question. What is the port connected with? And with >> what cable? Is it null modem cable? Or at least with DTR-CTS connected? > > Nothing is connected. After all, the whole point of this exercise is to > give the driver data to send which it can't get out so I can see whether > it blocks all tty operations system wide while trying to do the flush on > close. But according to the trace, it waits only in its queue... Well, could you turn on lockdep and dump sysrq-d when your echo is closing the port? thanks, -- js