From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2E875C432C3 for ; Tue, 3 Dec 2019 14:11:52 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id BA249206EC for ; Tue, 3 Dec 2019 14:11:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BA249206EC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=mentor.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:54258 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ic8u4-0003W3-MP for qemu-devel@archiver.kernel.org; Tue, 03 Dec 2019 09:11:49 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:48096) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ic3uI-0002vX-71 for qemu-devel@nongnu.org; Tue, 03 Dec 2019 03:51:44 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ic3uD-0007R4-Fc for qemu-devel@nongnu.org; Tue, 03 Dec 2019 03:51:39 -0500 Received: from esa2.mentor.iphmx.com ([68.232.141.98]:44122) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ic3uD-0007H2-5Y for qemu-devel@nongnu.org; Tue, 03 Dec 2019 03:51:37 -0500 IronPort-SDR: t0BeAo8JjLRuoJpZZgLEZSXTPdSQIBDeUwk+NlEnAQYaY/dCcLVHLQO0E51/DIeAn91+p+Ewf3 c33baJUCQJZrsrMsBajY3VV/aGCilygQpBS64sUpRngMviAIXkERrqYTl0k6H1VxMzEmlMB5Xl lr/5oap7UiuGjkKm+a0QzrzVeVb/5aDarjdH/YPIKrXb3Y+6uGrTgRoVgM4CHBs950G/Fpb33p RBCiyVJF4UMQVFaG5mHjHoX0DoCO8ruWiHEXBF/kaAPFF9rptEbQLEIet7t6ukipGMBC6Xnbe0 uw4= X-IronPort-AV: E=Sophos;i="5.69,272,1571731200"; d="scan'208";a="43651534" Received: from orw-gwy-02-in.mentorg.com ([192.94.38.167]) by esa2.mentor.iphmx.com with ESMTP; 03 Dec 2019 00:51:33 -0800 IronPort-SDR: V31aPAlTL4Jd77N/4vFkI/ULg0cF5PBYkzlUKlSwB5TqW2oengXeZXGIIUezjAPeS45uGXetRj k8fdcbh6lAth0z2rEc/o8A8Yjx1Gs9FJcj8ClHn/v7e9trEbTEqyktunDgxc+NGMNzDE3uUt+H tVPkPMHeGKWmqIn4OYYFVSQrHux/WyXhsdu22AjmEmoi5aXIBAP1OBiJIM2OD+5+c39ZCXjbpa 5nlSWx1IxowCPCDsJce0jzoNxMJv4XdCFGcMxbpF2S+x4ddCnnoky/Je4mZZIOCotBY7rKE4oJ 6+w= Subject: Re: [PATCH v3 5/7] gpio: Add GPIO Aggregator/Repeater driver To: Geert Uytterhoeven References: <20191127084253.16356-1-geert+renesas@glider.be> <20191127084253.16356-6-geert+renesas@glider.be> <585c4ad9-31fc-e87e-07c4-b8d6aa09c7e4@mentor.com> From: Harish Jenny K N Message-ID: Date: Tue, 3 Dec 2019 14:21:21 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Content-Language: en-US X-Originating-IP: [137.202.0.90] X-ClientProxiedBy: svr-ies-mbx-05.mgc.mentorg.com (139.181.222.5) To svr-ies-mbx-01.mgc.mentorg.com (139.181.222.1) X-detected-operating-system: by eggs.gnu.org: FreeBSD 9.x [fuzzy] X-Received-From: 68.232.141.98 X-Mailman-Approved-At: Tue, 03 Dec 2019 09:05:26 -0500 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Peter Maydell , QEMU Developers , Phil Reid , Geert Uytterhoeven , Jonathan Corbet , Marc Zyngier , Linus Walleij , "open list:DOCUMENTATION" , Magnus Damm , Christoffer Dall , Linux Kernel Mailing List , Linux-Renesas , Bartosz Golaszewski , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Rob Herring , Alexander Graf , "open list:GPIO SUBSYSTEM" , Paolo Bonzini , Eugeniu Rosca Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 03/12/19 1:47 PM, Geert Uytterhoeven wrote: > Hi Harish, > > On Tue, Dec 3, 2019 at 6:42 AM Harish Jenny K N > wrote: >>> +static int gpio_aggregator_probe(struct platform_device *pdev) >>> +{ >>> + struct device *dev = &pdev->dev; >>> + struct gpio_desc **descs; >>> + struct gpiochip_fwd *fwd; >>> + int i, n; >>> + >>> + n = gpiod_count(dev, NULL); >>> + if (n < 0) >>> + return n; >>> + >>> + descs = devm_kmalloc_array(dev, n, sizeof(*descs), GFP_KERNEL); >>> + if (!descs) >>> + return -ENOMEM; >>> + >>> + for (i = 0; i < n; i++) { >>> + descs[i] = devm_gpiod_get_index(dev, NULL, i, GPIOD_ASIS); >> can you please add this check as well as we need to return EPROBE_DEFER. >> >> if (desc[i] == ERR_PTR(-ENOENT)) >> < return -EPROBE_DEFER; > So gpiod_get_index() nevers return -EPROBE_DEFER, but returns -ENOENT > instead? > How can a driver distinguish between "GPIO not found" and "gpiochip driver > not yet initialized"? > Worse, so the *_optional() variants will return NULL in both cases, too, so > the caller will always fall back to optional GPIO not present? > > Or am I missing something? > > Gr{oetje,eeting}s, > > Geert We had earlier tested our changes on 4.14 kernel and the explicit return of -EPROBE_DEFER was needed in the inverter driver. probably the commit 6662ae6af82df10259a70c7569b4c12ea7f3ba93 ( gpiolib: Keep returning EPROBE_DEFER when we should) has fixed the issue and now it returns -EPROBE_DEFER.  you can ignore this comment as of now. I will test and let you know if needed. Thanks, Harish