From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751297Ab3LKHSw (ORCPT ); Wed, 11 Dec 2013 02:18:52 -0500 Received: from mail-pd0-f169.google.com ([209.85.192.169]:41813 "EHLO mail-pd0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750829Ab3LKHSv (ORCPT ); Wed, 11 Dec 2013 02:18:51 -0500 Message-ID: <52A811D1.1040908@gmail.com> Date: Wed, 11 Dec 2013 15:18:41 +0800 From: Haojian Zhuang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.1 MIME-Version: 1.0 To: Marek Vasut , Daniel Mack CC: Sergei Ianovich , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Eric Miao , Russell King , Igor Grinberg Subject: Re: [PATCH] ARM: pxa: prevent PXA270 occasional reboot freezes References: <1386650355-2503-1-git-send-email-ynvich@gmail.com> <52A6D44C.1010504@gmail.com> <52A6F19B.8090309@gmail.com> <201312101931.34108.marex@denx.de> In-Reply-To: <201312101931.34108.marex@denx.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/11/2013 02:31 AM, Marek Vasut wrote: > On Tuesday, December 10, 2013 at 11:48:59 AM, Daniel Mack wrote: >> On 12/10/2013 09:43 AM, Haojian Zhuang wrote: >>> On 12/10/2013 12:39 PM, Sergei Ianovich wrote: >>>> Erratum 71 of PXA270M Processor Family Specification Update >>>> (April 19, 2010) explains that watchdog reset time is just >>>> 8us insead of 10ms in EMTS. >>>> >>>> If SDRAM is not reset, it causes memory bus congestion and >>>> the device hangs. We put SDRAM in selfresh mode before watchdog >>>> reset, removing potential freezes. >>>> >>>> Without this patch PXA270-based ICP DAS LP-8x4x hangs after up to 40 >>>> reboots. With this patch it has successfully rebooted 500 times. >>>> >>>> Signed-off-by: Sergei Ianovich >>>> --- >>>> >>>> arch/arm/mach-pxa/reset.c | 8 +++++++- >>>> 1 file changed, 7 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/arch/arm/mach-pxa/reset.c b/arch/arm/mach-pxa/reset.c >>>> index 0d5dd64..263b152 100644 >>>> --- a/arch/arm/mach-pxa/reset.c >>>> +++ b/arch/arm/mach-pxa/reset.c >>>> @@ -13,6 +13,7 @@ >>>> >>>> #include >>>> #include >>>> >>>> +#include >>>> >>>> unsigned int reset_status; >>>> EXPORT_SYMBOL(reset_status); >>>> >>>> @@ -81,6 +82,12 @@ static void do_hw_reset(void) >>>> >>>> writel_relaxed(OSSR_M3, OSSR); >>>> /* ... in 100 ms */ >>>> writel_relaxed(readl_relaxed(OSCR) + 368640, OSMR3); >>>> >>>> + /* >>>> + * SDRAM hangs on watchdog reset on Marvell PXA270 (erratum 71) >>>> + * we put SDRAM into self-refresh to prevent that >>>> + */ >>>> + while (1) >>>> + writel_relaxed(MDREFR_SLFRSH, MDREFR); >>>> >>>> } >>>> >>>> void pxa_restart(enum reboot_mode mode, const char *cmd) >>>> >>>> @@ -104,4 +111,3 @@ void pxa_restart(enum reboot_mode mode, const char >>>> *cmd) >>>> >>>> break; >>>> >>>> } >>>> >>>> } >>>> >>>> - >>> >>> Hi Daniel/Marek/Igor, >>> >>> Could you help to try this patch? I'm lack of PXA27x board. >> >> I don't have any either right now ... > > On VPAC270 > > Tested-by: Marek Vasut > > Best regards, > Marek Vasut > Applied. Thanks Haojian