From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752533Ab3LJKtJ (ORCPT ); Tue, 10 Dec 2013 05:49:09 -0500 Received: from mail-ea0-f171.google.com ([209.85.215.171]:38711 "EHLO mail-ea0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751724Ab3LJKtE (ORCPT ); Tue, 10 Dec 2013 05:49:04 -0500 Message-ID: <52A6F19B.8090309@gmail.com> Date: Tue, 10 Dec 2013 11:48:59 +0100 From: Daniel Mack User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 MIME-Version: 1.0 To: Haojian Zhuang , Sergei Ianovich , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org CC: Eric Miao , Russell King , Marek Vasut , 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> In-Reply-To: <52A6D44C.1010504@gmail.com> X-Enigmail-Version: 1.5.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 ... Daniel