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=-3.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 8FBC0C433E0 for ; Tue, 16 Jun 2020 08:32:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6036320767 for ; Tue, 16 Jun 2020 08:32:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="yzgs82Ty" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727988AbgFPIcH (ORCPT ); Tue, 16 Jun 2020 04:32:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35362 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728038AbgFPIcH (ORCPT ); Tue, 16 Jun 2020 04:32:07 -0400 Received: from mail-lj1-x244.google.com (mail-lj1-x244.google.com [IPv6:2a00:1450:4864:20::244]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C8125C05BD43 for ; Tue, 16 Jun 2020 01:32:06 -0700 (PDT) Received: by mail-lj1-x244.google.com with SMTP id 9so22504255ljc.8 for ; Tue, 16 Jun 2020 01:32:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=sQ4U7wvoNlcpjuMW/4KAQuHPsQCChERlSO2SrjCLc4A=; b=yzgs82TyqjiolbSZa0hACzF4gN7GCdrUZ3PkJIwNsxrwGymEWug+COKC95YBk6TI0K 2Y0WbWcE0rB11ecpIHasmBOEfu2LHU1jVxms4CkS6c1YBhHphAVGDqxKnQPW4PBBc7hb LMdJwAntiTOBJmW2XA6P3lnRabzZ3UT3E9uy8o/U1SwZ5oitYwRLHc5WSAN8DB/8WxGH VrB15nm/FvXI/F5bPdrN/KsIQp6inbymvEpyLN7rdC7zEFqzsH+Jxw7zBeSbaDF9hj4Z jaXPYaexNoE0Z92Ldpp3NqRRd9Su8ihOkFK3xJAvMTKv498p1DzKxsLxehhJydEQaZ+i fWig== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=sQ4U7wvoNlcpjuMW/4KAQuHPsQCChERlSO2SrjCLc4A=; b=PVHcPOhgsVWqBnI4NE4YLmUNe9fNycXdLAetOZ/QiQkEy496AoaGonR4Xu47TboBhA L10/3w1ckrOsoAMldsqNj6tpp7KzICiZxwZkSkIbTwNqVMeEwxAnNwzkH802UgIWa/T/ jl32Rke+D1tsdLzaDHW5LH/zTSPMJZdfkFdb5R/AS0uR5vFc53W2IhA1YYd2FmDDh4BS VqX6yp099o3tihk0tB9R9clsXMssOquvrV5Q7Tmj/dUpC8xM0+94QzF0EMW9y+gPx/TQ zrNu9gfKgIV3NpqlmghOgtAPpcTj3vFPpDHrEjpz5Jg9dmmw+vN6+BgzJXLNulZXFsfi q3sA== X-Gm-Message-State: AOAM530a7f0cCG8DWslKSGUFpani+YEYeay6C8XeF+sAVA1rjUtH+jrC Pp2Oq7e8NrIlcBQllex8dyj60z9C08C1K+5pemLGPo545eA= X-Google-Smtp-Source: ABdhPJzDjr7Vp4IVSdnf58s8G/HEW2ciu0txbLcKtPfjhvTLWtyM16wHBxujqgvNRbb533tvY8VqBYbmo4AT2CdyIOc= X-Received: by 2002:a2e:350a:: with SMTP id z10mr837916ljz.104.1592296325111; Tue, 16 Jun 2020 01:32:05 -0700 (PDT) MIME-Version: 1.0 References: <20200608125143.GA2789203@x1> In-Reply-To: <20200608125143.GA2789203@x1> From: Linus Walleij Date: Tue, 16 Jun 2020 10:31:54 +0200 Message-ID: Subject: Re: [PATCH v2] pinctrl-single: fix pcs_parse_pinconf() return value To: Drew Fustini Cc: Tony Lindgren , Haojian Zhuang , Linux ARM , Linux-OMAP , "open list:GPIO SUBSYSTEM" , "linux-kernel@vger.kernel.org" , Grygorii Strashko , Jason Kridner , Robert Nelson Content-Type: text/plain; charset="UTF-8" Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org On Mon, Jun 8, 2020 at 2:51 PM Drew Fustini wrote: > This patch causes pcs_parse_pinconf() to return -ENOTSUPP when no > pinctrl_map is added. The current behavior is to return 0 when > !PCS_HAS_PINCONF or !nconfs. Thus pcs_parse_one_pinctrl_entry() > incorrectly assumes that a map was added and sets num_maps = 2. > > Analysis: > ========= > The function pcs_parse_one_pinctrl_entry() calls pcs_parse_pinconf() > if PCS_HAS_PINCONF is enabled. The function pcs_parse_pinconf() > returns 0 to indicate there was no error and num_maps is then set to 2: > > 980 static int pcs_parse_one_pinctrl_entry(struct pcs_device *pcs, > 981 struct device_node *np, > 982 struct pinctrl_map **map, > 983 unsigned *num_maps, > 984 const char **pgnames) > 985 { > > 1053 (*map)->type = PIN_MAP_TYPE_MUX_GROUP; > 1054 (*map)->data.mux.group = np->name; > 1055 (*map)->data.mux.function = np->name; > 1056 > 1057 if (PCS_HAS_PINCONF && function) { > 1058 res = pcs_parse_pinconf(pcs, np, function, map); > 1059 if (res) > 1060 goto free_pingroups; > 1061 *num_maps = 2; > 1062 } else { > 1063 *num_maps = 1; > 1064 } > > However, pcs_parse_pinconf() will also return 0 if !PCS_HAS_PINCONF or > !nconfs. I believe these conditions should indicate that no map was > added by returning -ENOTSUPP. Otherwise pcs_parse_one_pinctrl_entry() > will set num_maps = 2 even though no maps were successfully added, as > it does not reach "m++" on line 940: > > 895 static int pcs_parse_pinconf(struct pcs_device *pcs, struct device_node *np, > 896 struct pcs_function *func, > 897 struct pinctrl_map **map) > 898 > 899 { > 900 struct pinctrl_map *m = *map; > > 917 /* If pinconf isn't supported, don't parse properties in below. */ > 918 if (!PCS_HAS_PINCONF) > 919 return 0; > 920 > 921 /* cacluate how much properties are supported in current node */ > 922 for (i = 0; i < ARRAY_SIZE(prop2); i++) { > 923 if (of_find_property(np, prop2[i].name, NULL)) > 924 nconfs++; > 925 } > 926 for (i = 0; i < ARRAY_SIZE(prop4); i++) { > 927 if (of_find_property(np, prop4[i].name, NULL)) > 928 nconfs++; > 929 } > 930 if (!nconfs) > 919 return 0; > 932 > 933 func->conf = devm_kcalloc(pcs->dev, > 934 nconfs, sizeof(struct pcs_conf_vals), > 935 GFP_KERNEL); > 936 if (!func->conf) > 937 return -ENOMEM; > 938 func->nconfs = nconfs; > 939 conf = &(func->conf[0]); > 940 m++; > > This situtation will cause a boot failure [0] on the BeagleBone Black > (AM3358) when am33xx_pinmux node in arch/arm/boot/dts/am33xx-l4.dtsi > has compatible = "pinconf-single" instead of "pinctrl-single". > > The patch fixes this issue by returning -ENOSUPP when !PCS_HAS_PINCONF > or !nconfs, so that pcs_parse_one_pinctrl_entry() will know that no > map was added. > > Logic is also added to pcs_parse_one_pinctrl_entry() to distinguish > between -ENOSUPP and other errors. In the case of -ENOSUPP, num_maps > is set to 1 as it is valid for pinconf to be enabled and a given pin > group to not any pinconf properties. > > [0] https://lore.kernel.org/linux-omap/20200529175544.GA3766151@x1/ > > Fixes: 9dddb4df90d1 ("pinctrl: single: support generic pinconf") > Signed-off-by: Drew Fustini Patch applied as non-critical (for-next) fix. If there is no hurry let's merge it this way with lots of testing along the way. Yours, Linus Walleij