From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-bw0-f217.google.com (mail-bw0-f217.google.com [209.85.218.217]) by ozlabs.org (Postfix) with ESMTP id A2614B7C67 for ; Wed, 31 Mar 2010 19:32:24 +1100 (EST) Received: by bwz9 with SMTP id 9so1689859bwz.9 for ; Wed, 31 Mar 2010 01:32:22 -0700 (PDT) Date: Wed, 31 Mar 2010 12:32:18 +0400 From: Anton Vorontsov To: Bill Gatliff Subject: Re: Requesting a GPIO that hasn't been registered yet Message-ID: <20100331083218.GA15664@oksana.dev.rtsoft.ru> References: <4BB2BBDD.6050304@billgatliff.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 In-Reply-To: <4BB2BBDD.6050304@billgatliff.com> Cc: Linux/PPC Development List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, Mar 30, 2010 at 10:05:01PM -0500, Bill Gatliff wrote: [...] > In other words, the GPIO pin I'm using for the key is one of the bits on > my pca953x GPIO expander chip. > > The above would all be great, except that I haven't come up with a way > to make sure that my encoder_button doesn't try to probe before lext60 > is available. In fact, I'm consistently getting initialization in the > wrong order! > > Eventually the GPIO expander chip gets plugged in, because I can see it > show up in sysfs. And what's really odd is, I recently made similar > mods to gpio_leds and they are working fine--- although the GPIO pin is > on a pca953x at address 20, instead of 60. I'm at a loss to explain why > one works, but the other doesn't. And I don't know how to really fix > this problem for good! That's because of drivers/Makefile: obj-$(CONFIG_INPUT) += input/ ... obj-y += i2c/ media/ ... obj-$(CONFIG_NEW_LEDS) += leds/ So, all these drivers use module_init(), which means that the order of execution depends on link order. To fix probing you need to move i2c/ above input/: diff --git a/drivers/Makefile b/drivers/Makefile index 34f1e10..d31bb52 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -67,12 +67,12 @@ obj-$(CONFIG_USB) += usb/ obj-$(CONFIG_USB_MUSB_HDRC) += usb/musb/ obj-$(CONFIG_PCI) += usb/ obj-$(CONFIG_USB_GADGET) += usb/gadget/ +obj-y += i2c/ media/ obj-$(CONFIG_SERIO) += input/serio/ obj-$(CONFIG_GAMEPORT) += input/gameport/ obj-$(CONFIG_INPUT) += input/ obj-$(CONFIG_I2O) += message/ obj-$(CONFIG_RTC_LIB) += rtc/ -obj-y += i2c/ media/ obj-$(CONFIG_PPS) += pps/ obj-$(CONFIG_W1) += w1/ obj-$(CONFIG_POWER_SUPPLY) += power/