From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Sun, 11 Jan 2015 17:13:33 +0100 (CET) Received: from bh-25.webhostbox.net ([208.91.199.152]:35907 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S27011262AbbAKQNbiEvEl (ORCPT ); Sun, 11 Jan 2015 17:13:31 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=roeck-us.net; s=default; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:References:Subject:CC:To:MIME-Version:From:Date:Message-ID; bh=tnJb3N+tND2Iw/4rXqq/yu1oqTUEqZ+wqDY9/yL+Oo0=; b=1YKsoDxuNEqqwwxCAqg9LejDNwSJPGRy1R04nHpY24ARdxVx8Osgoxa8y/k7TGItTK7MnC+z57iCDalbp5HnSjqRaQ2waEe8G3/QSS4iQiQrmJ33SWLYs2iswxvssZImL5JzwfcbYP+P6qFEKcnD6h+J3YEhXb5Mr/TG0FsMFvI=; Received: from mailnull by bh-25.webhostbox.net with sa-checked (Exim 4.82) (envelope-from ) id 1YAL8n-0042Pm-Hk for linux-mips@linux-mips.org; Sun, 11 Jan 2015 16:13:25 +0000 Received: from 108-223-40-66.lightspeed.sntcca.sbcglobal.net ([108.223.40.66]:57128 helo=server.roeck-us.net) by bh-25.webhostbox.net with esmtpsa (TLSv1:DHE-RSA-AES128-SHA:128) (Exim 4.82) (envelope-from ) id 1YAL8l-0042IB-Dy; Sun, 11 Jan 2015 16:13:24 +0000 Message-ID: <54B2A120.9040504@roeck-us.net> Date: Sun, 11 Jan 2015 08:13:20 -0800 From: Guenter Roeck User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-Version: 1.0 To: Lars-Peter Clausen , =?windows-1252?Q?M=E5ns_Rullg?= =?windows-1252?Q?=E5rd?= CC: Ralf Baechle , Wim Van Sebroeck , Paul Burton , Paul Cercueil , Maarten ter Huurne , linux-mips@linux-mips.org, linux-watchdog@vger.kernel.org Subject: Re: [PATCH 1/3] MIPS: Use do_kernel_restart() as the default restart handler References: <1420914550-18335-1-git-send-email-lars@metafoo.de> <54B1CF9B.3060606@roeck-us.net> <54B26BB4.50707@metafoo.de> In-Reply-To: <54B26BB4.50707@metafoo.de> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit X-Authenticated_sender: linux@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-CTCH-PVer: 0000001 X-CTCH-Spam: Unknown X-CTCH-VOD: Unknown X-CTCH-Flags: 0 X-CTCH-RefID: str=0001.0A020202.54B2A125.001E,ss=1,re=0.001,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0 X-CTCH-Score: 0.001 X-CTCH-ScoreCust: 0.000 X-CTCH-Rules: C_4847, X-CTCH-SenderID: linux@roeck-us.net X-CTCH-SenderID-Flags: 0 X-CTCH-SenderID-TotalMessages: 2 X-CTCH-SenderID-TotalSpam: 0 X-CTCH-SenderID-TotalSuspected: 0 X-CTCH-SenderID-TotalConfirmed: 0 X-CTCH-SenderID-TotalBulk: 0 X-CTCH-SenderID-TotalVirus: 0 X-CTCH-SenderID-TotalRecipients: 0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - linux-mips.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: mailgid no entry from get_relayhosts_entry X-Source: X-Source-Args: X-Source-Dir: Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 45070 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: linux@roeck-us.net Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips On 01/11/2015 04:25 AM, Lars-Peter Clausen wrote: > On 01/11/2015 01:15 PM, Måns Rullgård wrote: >> Guenter Roeck writes: >> >>> On 01/10/2015 12:08 PM, Måns Rullgård wrote: >>>> Lars-Peter Clausen writes: >>>> >>>>> Use the recently introduced do_kernel_restart() function as the default restart >>>>> handler if the platform did not explicitly provide a restart handler. This >>>>> allows use restart handler that have been registered by device drivers to >>>>> restart the machine. >>>>> >>>>> Signed-off-by: Lars-Peter Clausen >>>>> --- >>>>> arch/mips/kernel/reset.c | 2 +- >>>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>>> >>>>> diff --git a/arch/mips/kernel/reset.c b/arch/mips/kernel/reset.c >>>>> index 07fc524..36cd80c 100644 >>>>> --- a/arch/mips/kernel/reset.c >>>>> +++ b/arch/mips/kernel/reset.c >>>>> @@ -19,7 +19,7 @@ >>>>> * So handle all using function pointers to machine specific >>>>> * functions. >>>>> */ >>>>> -void (*_machine_restart)(char *command); >>>>> +void (*_machine_restart)(char *command) = do_kernel_restart; >>>>> void (*_machine_halt)(void); >>>>> void (*pm_power_off)(void); >>>> >>>> There is already a similar patch posted by Kevin Cernekee: >>>> http://www.linux-mips.org/archives/linux-mips/2014-12/msg00410.html >>>> >>> Personally I prefer the earlier patch, though I guess that is personal >>> preference. >> >> They both achieve the same thing, though Kevin's is more in line with >> what ARM does. Missing from both is a fallback while(1) loop in case no >> restart handlers are registered. With the restart moved to the watchdog >> driver, there's a possibility that this might happen. >> > > In my opinion if such a fallback is needed it should be put into the kernel core reboot implementation and not into individual restart handler implementations. > Agreed. > My first version of this patch was do_kernel_restart() followed by a machine_halt() (so it goes to sleep instead of busy looping) as a fallback. But I couldn't find a good reason why that should be done at the individual restart handler level, so I dropped it. > That should probably be added to do_kernel_restart(). Guenter