Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753563AbaG2NCM (ORCPT ); Tue, 29 Jul 2014 09:02:12 -0400 Received: from mail-pd0-f178.google.com ([209.85.192.178]:48126 "EHLO mail-pd0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752764AbaG2NCK (ORCPT ); Tue, 29 Jul 2014 09:02:10 -0400 Message-ID: <53D79B03.5020104@linaro.org> Date: Tue, 29 Jul 2014 21:00:51 +0800 From: Hanjun Guo User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Sudeep Holla , Catalin Marinas , "Rafael J. Wysocki" , Mark Rutland CC: "graeme.gregory@linaro.org" , Arnd Bergmann , "grant.likely@linaro.org" , Will Deacon , Jason Cooper , Marc Zyngier , Bjorn Helgaas , Daniel Lezcano , Mark Brown , Robert Richter , Lv Zheng , Robert Moore , Lorenzo Pieralisi , Liviu Dudau , Randy Dunlap , Charles Garcia-Tobin , "linux-acpi@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 03/19] ARM64 / ACPI: Introduce lowlevel suspend function References: <1406206825-15590-1-git-send-email-hanjun.guo@linaro.org> <1406206825-15590-4-git-send-email-hanjun.guo@linaro.org> <53D69665.5090709@arm.com> In-Reply-To: <53D69665.5090709@arm.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2014-7-29 2:28, Sudeep Holla wrote: > > > On 24/07/14 14:00, Hanjun Guo wrote: >> From: Graeme Gregory >> >> acpi_wakeup_address is used on x86 as the address bios jumps into >> when machine wakes up from suspend. As arm64 does not have such a >> bios this mechanism will be provided by other means. But the define >> is still required inside the acpi core. >> >> Introduce a null stub for acpi_suspend_lowlevel as this is also >> required by core. This will be filled in when standards are >> defined for arm64 ACPI global power states. >> >> Reviewed-by: Grant Likely >> Signed-off-by: Graeme Gregory >> Signed-off-by: Hanjun Guo >> --- >> arch/arm64/include/asm/acpi.h | 12 ++++++++++++ >> arch/arm64/kernel/acpi.c | 7 +++++++ >> 2 files changed, 19 insertions(+) >> >> diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h >> index e8581ea..44b617f 100644 >> --- a/arch/arm64/include/asm/acpi.h >> +++ b/arch/arm64/include/asm/acpi.h >> @@ -36,6 +36,18 @@ static inline bool acpi_has_cpu_in_madt(void) >> return 1; >> } >> >> +/* Low-level suspend routine. >> + * >> + * ACPI S-states for ARM64 have to be defined >> + * and approved before doing anything else, maybe >> + * we need update the ACPI spec, here we >> + * just introduce function and macro needed by >> + * ACPI core as IA64 did, and revisit them when >> + * the spec is ready. >> + */ >> +extern int (*acpi_suspend_lowlevel)(void); >> +#define acpi_wakeup_address 0 >> + > > While I understand that this is temporary solution, but will this be > sufficient to make sure we don't enter acpi_suspend_enter ? > > A brief look at acpi_suspend_enter showed access to write to > ACPI_BITREG_SCI_ENABLE which might just explode. But if you are sure that > it will not be executed, then it should be fine for now. I think it will not be executed, since ARM64 do not support S1 and S3 in ACPI for now, and that state will not defined, then acpi_suspend_enter will not be called. Thanks Hanjun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/