From mboxrd@z Thu Jan 1 00:00:00 1970 From: marex@denx.de (Marek Vasut) Date: Tue, 10 Dec 2013 19:31:34 +0100 Subject: [PATCH] ARM: pxa: prevent PXA270 occasional reboot freezes In-Reply-To: <52A6F19B.8090309@gmail.com> References: <1386650355-2503-1-git-send-email-ynvich@gmail.com> <52A6D44C.1010504@gmail.com> <52A6F19B.8090309@gmail.com> Message-ID: <201312101931.34108.marex@denx.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752415Ab3LJSmc (ORCPT ); Tue, 10 Dec 2013 13:42:32 -0500 Received: from mail-out.m-online.net ([212.18.0.9]:32785 "EHLO mail-out.m-online.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751211Ab3LJSm1 (ORCPT ); Tue, 10 Dec 2013 13:42:27 -0500 X-Auth-Info: fa2oyrMQVCX0oJuLYkify0t77jMXIcmfgNQFxaEt7H8= From: Marek Vasut To: Daniel Mack Subject: Re: [PATCH] ARM: pxa: prevent PXA270 occasional reboot freezes Date: Tue, 10 Dec 2013 19:31:34 +0100 User-Agent: KMail/1.13.7 (Linux/3.10-2-amd64; KDE/4.10.5; x86_64; ; ) Cc: Haojian Zhuang , Sergei Ianovich , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Eric Miao , Russell King , Igor Grinberg References: <1386650355-2503-1-git-send-email-ynvich@gmail.com> <52A6D44C.1010504@gmail.com> <52A6F19B.8090309@gmail.com> In-Reply-To: <52A6F19B.8090309@gmail.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Message-Id: <201312101931.34108.marex@denx.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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