Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966129AbbBCRVP (ORCPT ); Tue, 3 Feb 2015 12:21:15 -0500 Received: from foss-mx-na.foss.arm.com ([217.140.108.86]:40938 "EHLO foss-mx-na.foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756030AbbBCRVL (ORCPT ); Tue, 3 Feb 2015 12:21:11 -0500 Date: Tue, 3 Feb 2015 17:20:48 +0000 From: Catalin Marinas To: Hanjun Guo Cc: "Rafael J. Wysocki" , Olof Johansson , Arnd Bergmann , Mark Rutland , "grant.likely@linaro.org" , Will Deacon , Lorenzo Pieralisi , "graeme.gregory@linaro.org" , Sudeep Holla , "jcm@redhat.com" , Jason Cooper , Marc Zyngier , Bjorn Helgaas , Daniel Lezcano , Mark Brown , Rob Herring , Robert Richter , Randy Dunlap , Charles Garcia-Tobin , "phoenix.liyi@huawei.com" , Timur Tabi , Ashwin Chaugule , "suravee.suthikulpanit@amd.com" , Mark Langsdorf , "wangyijing@huawei.com" , "linux-acpi@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "linaro-acpi@lists.linaro.org" Subject: Re: [PATCH v8 09/21] ARM64 / ACPI: Disable ACPI if FADT revision is less than 5.1 Message-ID: <20150203172047.GA13339@e104818-lin.cambridge.arm.com> References: <1422881149-8177-1-git-send-email-hanjun.guo@linaro.org> <1422881149-8177-10-git-send-email-hanjun.guo@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1422881149-8177-10-git-send-email-hanjun.guo@linaro.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2538 Lines: 76 On Mon, Feb 02, 2015 at 12:45:37PM +0000, Hanjun Guo wrote: > diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c > index afe10b4..b9f64ec 100644 > --- a/arch/arm64/kernel/acpi.c > +++ b/arch/arm64/kernel/acpi.c > @@ -13,6 +13,8 @@ > * published by the Free Software Foundation. > */ > > +#define pr_fmt(fmt) "ACPI: " fmt > + > #include > #include > #include > @@ -49,10 +51,32 @@ void __init __acpi_unmap_table(char *map, unsigned long size) > early_memunmap(map, size); > } > > +static int __init acpi_parse_fadt(struct acpi_table_header *table) > +{ > + struct acpi_table_fadt *fadt = (struct acpi_table_fadt *)table; > + > + /* > + * Revision in table header is the FADT Major revision, and there > + * is a minor revision of FADT which was introduced by ACPI 5.1, > + * we only deal with ACPI 5.1 or newer revision to get GIC and SMP > + * boot protocol configuration data, or we will disable ACPI. > + */ > + if (table->revision > 5 || > + (table->revision == 5 && fadt->minor_revision >= 1)) > + return 0; > + > + pr_warn("Unsupported FADT revision %d.%d, should be 5.1+, will disable ACPI\n", > + table->revision, fadt->minor_revision); > + disable_acpi(); > + > + return -EINVAL; > +} > + > /* > * acpi_boot_table_init() called from setup_arch(), always. > * 1. find RSDP and get its address, and then find XSDT > * 2. extract all tables and checksums them all > + * 3. check ACPI FADT revision > * > * We can parse ACPI boot-time tables such as MADT after > * this function is called. > @@ -64,8 +88,16 @@ void __init acpi_boot_table_init(void) > return; > > /* Initialize the ACPI boot-time table parser. */ > - if (acpi_table_init()) > + if (acpi_table_init()) { > + disable_acpi(); > + return; > + } > + > + if (acpi_table_parse(ACPI_SIG_FADT, acpi_parse_fadt)) { > + /* disable ACPI if no FADT is found */ > disable_acpi(); > + pr_err("Can't find FADT\n"); > + } > } It looks fine to call disable_acpi() here but a bit weird to call it again in acpi_parse_fadt(). I guess that's because acpi_table_parse() ignores the return value of the handler() call. I think it's better to fix the core code (can be an additional patch on top of this series). -- Catalin -- 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/