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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 930A5CDB47E for ; Fri, 20 Oct 2023 07:35:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1376390AbjJTHfC (ORCPT ); Fri, 20 Oct 2023 03:35:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45970 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1376317AbjJTHfB (ORCPT ); Fri, 20 Oct 2023 03:35:01 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 125BD91; Fri, 20 Oct 2023 00:35:00 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7958EC433C7; Fri, 20 Oct 2023 07:34:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1697787299; bh=LuJ0EX2tXxho4nJTr8yfLdNrGYlhYAkXm6+rPpQQTKI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=aYIXA7yuJplTFlsba10PHWyASznbHDLRFDB1Jbh0PbjcXOEe1sFLkMRCecB1EYRPw 65SCVp8asIlIr+gB/DNrCBi/csSwpm5QSWAKuGlYl35CNWAkMySMBHc7Tqd/Xnk7Kh 8nKuUmiidgseqR5T2PKMLRIFJaJGQNNAT27u6XnXazxKPplRGpGc000k9nfFf8MALF FG1TOtK9vc2s70blsMD1P1OUg8/ZdUV36EZuLxZhNwxkYV0RVqkOdUSHbr+TziOSPH snu0m8rJhKyD25djVPC2Fd+9TOaWIk0HxJJrfutiU1j5MMhf4u6C7ySG/0law8D/UD uKs0mfs2ie/4w== Date: Fri, 20 Oct 2023 08:34:49 +0100 From: Jonathan Cameron To: Herve Codina Cc: Wolfram Sang , Peter Rosin , Stephen Warren , Rob Herring , Greg Kroah-Hartman , Wolfram Sang , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, Allan Nielsen , Horatiu Vultur , Steen Hegelund , Thomas Petazzoni Subject: Re: [PATCH v2 1/3] i2c: muxes: i2c-mux-pinctrl: Use of_get_i2c_adapter_by_node() Message-ID: <20231020083449.3393191f@jic23-huawei> In-Reply-To: <20231019101017.425284-2-herve.codina@bootlin.com> References: <20231019101017.425284-1-herve.codina@bootlin.com> <20231019101017.425284-2-herve.codina@bootlin.com> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org On Thu, 19 Oct 2023 12:10:14 +0200 Herve Codina wrote: > i2c-mux-pinctrl uses the pair of_find_i2c_adapter_by_node() / > i2c_put_adapter(). These pair alone is not correct to properly lock the > I2C parent adapter. > > Indeed, i2c_put_adapter() decrements the module refcount while > of_find_i2c_adapter_by_node() does not increment it. This leads to an > underflow of the parent module refcount. > > Use the dedicated function, of_get_i2c_adapter_by_node(), to handle > correctly the module refcount. > > Fixes: c4aee3e1b0de ("i2c: mux: pinctrl: remove platform_data") > Signed-off-by: Herve Codina > Acked-by: Peter Rosin Reviewed-by: Jonathan Cameron > --- > drivers/i2c/muxes/i2c-mux-pinctrl.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/i2c/muxes/i2c-mux-pinctrl.c b/drivers/i2c/muxes/i2c-mux-pinctrl.c > index 18236b9fa14a..6ebca7bfd8a2 100644 > --- a/drivers/i2c/muxes/i2c-mux-pinctrl.c > +++ b/drivers/i2c/muxes/i2c-mux-pinctrl.c > @@ -62,7 +62,7 @@ static struct i2c_adapter *i2c_mux_pinctrl_parent_adapter(struct device *dev) > dev_err(dev, "Cannot parse i2c-parent\n"); > return ERR_PTR(-ENODEV); > } > - parent = of_find_i2c_adapter_by_node(parent_np); > + parent = of_get_i2c_adapter_by_node(parent_np); > of_node_put(parent_np); > if (!parent) > return ERR_PTR(-EPROBE_DEFER);