Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751287AbbEAWnu (ORCPT ); Fri, 1 May 2015 18:43:50 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:48831 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751162AbbEAWnn (ORCPT ); Fri, 1 May 2015 18:43:43 -0400 MIME-Version: 1.0 In-Reply-To: References: Date: Fri, 1 May 2015 17:43:39 -0500 Message-ID: Subject: Re: [PATCH 15/17] ACPICA/ARM: ACPI 5.1: Update for GTDT table changes. From: Timur Tabi To: Lv Zheng Cc: "Rafael J. Wysocki" , Len Brown , Lv Zheng , lkml , linux-acpi@vger.kernel.org, Tomasz Nowicki , Hanjun Guo , Bob Moore Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2026 Lines: 60 On Tue, Jul 29, 2014 at 11:21 PM, Lv Zheng wrote: > From: Tomasz Nowicki > > New fields and new subtables. Tomasz Nowicki. > tomasz.nowicki@linaro.org > > Signed-off-by: Tomasz Nowicki > Signed-off-by: Hanjun Guo > Signed-off-by: Bob Moore > Signed-off-by: Lv Zheng Hi, I know this patch is old, but something confuses me about it: > +/* Common GTDT subtable header */ > + > +struct acpi_gtdt_header { > + u8 type; > + u16 length; > +}; I'm trying to write a function that parses the watchdog structure (acpi_gtdt_watchdog). The first entry in that structure is acpi_gtdt_header. Looking at the ACPI specification, I see that this is correct: the type is one byte, and the length is two bytes. However, this means that I cannot use acpi_parse_entries() to parse the watchdog subtable: int __init acpi_parse_entries(char *id, unsigned long table_size, acpi_tbl_entry_handler handler, struct acpi_table_header *table_header, int entry_id, unsigned int max_entries) acpi_tbl_entry_handler takes an acpi_subtable_header as its first parameter. However, that structure looks like this: struct acpi_subtable_header { u8 type; u8 length; }; This is not compatible, so I'm confused now. How do I properly parse the watchdog subtable, if I cannot use acpi_parse_entries? For context, here is my patch: http://www.spinics.net/lists/linux-watchdog/msg06240.html Scroll down to function arm_sbsa_wdt_parse_gtdt(). The typecast in first line is invalid: + struct acpi_gtdt_watchdog *wdg = (struct acpi_gtdt_watchdog *)header; because of the mismatch. I don't know how to fix this. -- 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/