From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752293Ab1AVRVz (ORCPT ); Sat, 22 Jan 2011 12:21:55 -0500 Received: from mail-ww0-f44.google.com ([74.125.82.44]:34643 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751515Ab1AVRVx convert rfc822-to-8bit (ORCPT ); Sat, 22 Jan 2011 12:21:53 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type:content-transfer-encoding; b=ivklu17Te60h7VYdGY8h1GI507FsuVR534YJgvvfysALw2jH2iNjp0ygQgJKhabb3K 9VoiXGJOsI8OgN7+8kgEAbjl4CuZ4XIZ92y/eavfQtgexaHIqvtFoKq/sBRhHvX+b+Io KJElxbuzwrbBIkWMv/YrEEV6s1GYFO6nJGdLc= MIME-Version: 1.0 In-Reply-To: <87tyh1bvgt.fsf@ti.com> References: <1295426461-12459-1-git-send-email-weber@corscience.de> <20110119130049.GB9365@m-desktop> <4D36E7CC.5090303@corscience.de> <20110120114855.GD1987@m-desktop> <38f2b3af600ce3dfea1e73edec7c81fa@mail.gmail.com> <20110121074530.GB12307@m-desktop> <87tyh1bvgt.fsf@ti.com> From: Govindraj Date: Sat, 22 Jan 2011 22:43:46 +0530 Message-ID: Subject: Re: [PATCHv2] OMAP: Enable Magic SysRq on serial console ttyOx To: Kevin Hilman Cc: "G, Manjunath Kondaiah" , Anand Gadiyar , Thomas Weber , linux-omap@vger.kernel.org, Tony Lindgren , Govindraj Raja , Greg Kroah-Hartman , Andrei Emeltchenko , linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jan 22, 2011 at 6:33 AM, Kevin Hilman wrote: > "G, Manjunath Kondaiah" writes: > >> On Fri, Jan 21, 2011 at 12:54:29PM +0530, Govindraj wrote: >>> On Thu, Jan 20, 2011 at 5:49 PM, Anand Gadiyar wrote: >>> >> > >>>> Magic SysRq key is not working for OMAP on new serial >>> >> > >>>> console ttyOx because SUPPORT_SYSRQ is not defined >>> >> > >>>> for omap-serial. >>> >> > >>>> >>> >> > >>>> This patch defines SUPPORT_SYSRQ in omap-serial and >>> >> > >>>> enables handling of Magic SysRq character. >>> >> > >>>> >>> >> > >>>> Signed-off-by: Thomas Weber >>> >> > >>> >>> >> > >>> Looks fine to me. >>> >> > >>> >>> >> > >>> Acked-by: Govindraj.R >>> >> > >> I tried to use SysRq key on minicom after applying this patch, it >>> > looks >>> >> > >> like it is not triggering sysrq event. >>> >> > >> >>> >> > >> Am I missing anything? >>> >> > >> >>> >> > >> -Manjunath >>> >> > >> -- >>> >> > > Hello Manjunath, >>> >> > > >>> >> > > Do you have CONFIG_MAGIC_SYSRQ enabled? >>> >> > > Magic SysRq key in Kernel Hacking >>> >> > > >>> >> > > I tested it on Devkit8000 (beagle board clone). >>> >> > > >>> >> > >>> >> > re-setting lsr_break_flag to 0 in receive chars is causing issues >>> >> > in getting sysrq key break sequence on omap-serial.c >>> >> > >>> >> > Manju, >>> >> > >>> >> > can you try this change on your environment. >>> >> > With below change works for me on 3430SDP/4430SDP. >>> >> > key sequence I checked. >>> >> > [alt + b + t]  => shows trace of tasks running. >>> >> > [alt + b + b] => system reboot. >>> >> >>> >> With below patch, it works fine on TeraTerm. However, I am not able to >>> >> perform the same on minicom. >>> >> >>> >> Tested-by: Manjunath G Kondaiah >>> >> >>> >> -Manjunath >>> >> >>> > >>> > Not sure what you guys are trying out, but I am able to use sysrq >>> > just fine in minicom (using only Thomas' original patch) - you need >>> > to send a break sequence, and the way to do this in minicom is to >>> > do Ctrl-A followed by F. >>> > >>> > Works for me, without the "resetting lsr_break_flag to 0" part. >>> > >>> > @Govind, >>> > >>> > What are the issues you see in getting sysrq key break sequence >>> > without your change? And how is your change fixing this? >>> >>> Actually I was using teraterm on windows platform. >>> using keyboard to send a break char [alt + b] sometimes >>> i observed that first break char was getting lost and subsequent break >>> chars where getting >>> recognized. However using send break option from terterm menu seems to >>> work most of times. >>> my change can be dropped. >> If it is fixing the issue of losing first break character, what is wrong in >> having this patch? >> >> Do you see any other issues because of this change? > > Were you loosing the first break character because of PM?  i.e., if the > OMAP is in retention or off while idle, we will always loose the first > character.  The first character causes the wakeup, but does not make it > to the UART. > No, even without PM i.e., even without setting sleep_while_idle and timeouts for uart I observed on windows-teraterm sometimes first break char was getting lost. -- Thanks, Govindraj.R