Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753543AbbGBI7z (ORCPT ); Thu, 2 Jul 2015 04:59:55 -0400 Received: from mail-ob0-f180.google.com ([209.85.214.180]:34161 "EHLO mail-ob0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752974AbbGBI7q (ORCPT ); Thu, 2 Jul 2015 04:59:46 -0400 MIME-Version: 1.0 In-Reply-To: References: <1435754753-31307-1-git-send-email-tomeu.vizoso@collabora.com> <1435754753-31307-2-git-send-email-tomeu.vizoso@collabora.com> Date: Thu, 2 Jul 2015 10:59:45 +0200 X-Google-Sender-Auth: RF784nAr1vK1S7PQgtP7vnibk6M Message-ID: Subject: Re: [PATCH v1 1/3] gpio: defer probe if pinctrl cannot be found From: Geert Uytterhoeven To: Rob Herring Cc: Tomeu Vizoso , "linux-kernel@vger.kernel.org" , "linux-gpio@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-tegra@vger.kernel.org" , Linus Walleij , Grant Likely , Rob Herring , Alexandre Courbot Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2029 Lines: 49 Hi Rob, On Wed, Jul 1, 2015 at 7:36 PM, Rob Herring wrote: > On Wed, Jul 1, 2015 at 7:45 AM, Tomeu Vizoso wrote: >> When an OF node has a pin range for its GPIOs, return -EPROBE_DEFER if >> the pin controller isn't available. >> >> Otherwise, the GPIO range wouldn't be set at all unless the pin >> controller probed always before the GPIO chip. >> >> With this change, the probe of the GPIO chip will be deferred and will >> be retried at a later point, hopefully once the pin controller has been >> registered and probed already. > > This will break cases where the pinctrl driver does not exist, but the > DT contains pinctrl bindings. We can have similar problems already > with clocks though. However, IMO this problem is a bit different in > that pinctrl is more likely entirely optional while clocks are often > required. You may do all pin setup in bootloader/firmware on some > boards and not others. Of course then why put pinctrl in the DT in > that case? They could be present just due to how chip vs. board dts > files are structured. Isn't that already the case? If I change the compatible value of a pinctrl node to an invalid value, I get: sh-sci e6c50000.serial: could not find pctldev for node /pfc@e6050000/serial1, deferring probe > We could address this by simply marking the pin controller node > disabled. However, ... Doesn't seem to make any difference. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- 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/