From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.4 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 25F6AC04AB1 for ; Thu, 9 May 2019 09:40:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F1684216C4 for ; Thu, 9 May 2019 09:40:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726576AbfEIJkw (ORCPT ); Thu, 9 May 2019 05:40:52 -0400 Received: from foss.arm.com ([217.140.101.70]:36184 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726281AbfEIJkw (ORCPT ); Thu, 9 May 2019 05:40:52 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E2805374; Thu, 9 May 2019 02:40:51 -0700 (PDT) Received: from e107155-lin (e107155-lin.cambridge.arm.com [10.1.196.42]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2150C3F575; Thu, 9 May 2019 02:40:49 -0700 (PDT) Date: Thu, 9 May 2019 10:40:44 +0100 From: Sudeep Holla To: Prasad Sodagudi Cc: julien.thierry@arm.com, will.deacon@arm.com, catalin.marinas@arm.com, mark.rutland@arm.com, lorenzo.pieralisi@arm.com, akpm@linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Sudeep Holla Subject: Re: [PATCH] kernel/panic: Use SYSTEM_RESET2 command for warm reset Message-ID: <20190509094021.GA8239@e107155-lin> References: <1557366432-352469-1-git-send-email-psodagud@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1557366432-352469-1-git-send-email-psodagud@codeaurora.org> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 08, 2019 at 06:47:12PM -0700, Prasad Sodagudi wrote: > Some platforms may need warm reboot support when kernel crashed > for post mortem analysis instead of cold reboot. So use config > CONFIG_WARM_REBOOT_ON_PANIC and SYSTEM_RESET2 psci command > support for warm reset. > Please drop all the references to PSCI and SYSTEM_RESET2 including in subject. This is more generic and PSCIv1.1 with SYSTEM_RESET2 can make use of it. > Signed-off-by: Prasad Sodagudi > --- > kernel/panic.c | 4 ++++ > lib/Kconfig.debug | 10 ++++++++++ > 2 files changed, 14 insertions(+) > > diff --git a/kernel/panic.c b/kernel/panic.c > index c1fcaad..6ab6675 100644 > --- a/kernel/panic.c > +++ b/kernel/panic.c > @@ -198,6 +198,10 @@ void panic(const char *fmt, ...) > > console_verbose(); > bust_spinlocks(1); > +#ifdef CONFIG_WARM_REBOOT_ON_PANIC > + /* Configure for warm reboot instead of cold reboot. */ > + reboot_mode = REBOOT_WARM; > +#endif > va_start(args, fmt); > len = vscnprintf(buf, sizeof(buf), fmt, args); > va_end(args); > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug > index d695ec1..2a727d8 100644 > --- a/lib/Kconfig.debug > +++ b/lib/Kconfig.debug > @@ -1000,6 +1000,16 @@ config PANIC_TIMEOUT > value n > 0 will wait n seconds before rebooting, while a timeout > value n < 0 will reboot immediately. > > +config WARM_REBOOT_ON_PANIC > + bool "Warm reboot instead of cold reboot for panic" > + default n > + help > + Some vendor platform may need warm reboot instead of cold reboot > + for debugging. Before vendor specific power off driver is > + probed, platform always gets cold reset. By setting Y here and > + support for PSCI V1.1 is present from firmware, platform would > + get warm reset instead of cold reset. > + Ditto here, drop PSCI reference. Since it's being pushed as generic solution, expecting anyone reading this to understand what is this PSCI makes no sense and may be even confusing. -- Regards, Sudeep