From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752574Ab1FQKvN (ORCPT ); Fri, 17 Jun 2011 06:51:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:16445 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751086Ab1FQKvL (ORCPT ); Fri, 17 Jun 2011 06:51:11 -0400 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <20110616102209.GC5262@opensource.wolfsonmicro.com> References: <20110616102209.GC5262@opensource.wolfsonmicro.com> <20110615144823.GA2806@opensource.wolfsonmicro.com> <1306921767-31115-1-git-send-email-broonie@opensource.wolfsonmicro.com> <5194.1308074912@redhat.com> <19624.1308206191@redhat.com> To: Mark Brown Cc: dhowells@redhat.com, linux-kernel@vger.kernel.org, grant@secretlab.ca, ralf@linux-mips.org Subject: Re: [PATCH] FRV: Hook up gpiolib support Date: Fri, 17 Jun 2011 11:50:59 +0100 Message-ID: <28714.1308307859@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Mark Brown wrote: > And to repeat what I said: the generic header prototypes everything it > needs before it uses it so there should be no problem here, it's not > been a problem on the other architectures using this code verbatim. > Please be more specific. Okay: CC drivers/mtd/maps/gpio-addr-flash.o In file included from /data/frv/linux-2.6-frv/arch/frv/include/asm/gpio.h:21, from include/linux/gpio.h:8, from drivers/mtd/maps/gpio-addr-flash.c:17: include/asm-generic/gpio.h: In function 'gpio_get_value_cansleep': include/asm-generic/gpio.h:233: error: implicit declaration of function 'gpio_get_value' include/asm-generic/gpio.h: In function 'gpio_set_value_cansleep': include/asm-generic/gpio.h:239: error: implicit declaration of function 'gpio_set_value' drivers/mtd/maps/gpio-addr-flash.c: In function 'gpio_flash_probe': drivers/mtd/maps/gpio-addr-flash.c:234: error: implicit declaration of function 'gpio_request' drivers/mtd/maps/gpio-addr-flash.c:238: error: implicit declaration of function 'gpio_free' drivers/mtd/maps/gpio-addr-flash.c:242: error: implicit declaration of function 'gpio_direction_output' Let me expand on my explanation earlier: (1) asm-generic/gpio.h has an _inline_ function: static inline int gpio_get_value_cansleep(unsigned gpio) { might_sleep(); return gpio_get_value(gpio); } (2) gpio_get_value() is implemented in asm/gpio.h. It is not declared in asm-generic/gpio.h. (3) Therefore, the #inclusion of asm-generic/gpio.h must come _after_ the implementation of gpio_get_value() in asm/gpio.h. (4) asm/gpio.h implements the aforementioned inline function: static inline int gpio_get_value(unsigned int gpio) { return __gpio_get_value(gpio); } (5) __gpio_get_value() is declared in asm-generic/gpio.h. It is not declared in asm/gpio.h. (6) Therefore, the #inclusion of asm/gpio.h must come _before_ the implementation of gpio_get_value() in asm/gpio.h. Thus (3) and (6) contradict. David