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=-5.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, USER_AGENT_MUTT autolearn=ham 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 65FD4C43441 for ; Mon, 26 Nov 2018 15:34:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2B46F20862 for ; Mon, 26 Nov 2018 15:34:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="iQmdsfac" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2B46F20862 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726987AbeK0C2u (ORCPT ); Mon, 26 Nov 2018 21:28:50 -0500 Received: from mail-ed1-f65.google.com ([209.85.208.65]:36735 "EHLO mail-ed1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726224AbeK0C2u (ORCPT ); Mon, 26 Nov 2018 21:28:50 -0500 Received: by mail-ed1-f65.google.com with SMTP id f23so16223745edb.3; Mon, 26 Nov 2018 07:34:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=jVvvSlcDW1rccwafybYx7K4mL+Q61eyXYRbJr4hiI0E=; b=iQmdsfacT9ox7RUgyDg3TtMjkgaENUWQREXsl+yOUP6kS50rpu1XiTx9bn3M/Lv4O4 2dkeMCyQZzvBPGH32mtyWP0izZTz2S6U1qv5RZgrpeZf0ZYer2TrLvBHwxhOCXI1k9F3 grkeXgW1DqPMMNAKmq8iH1u+FzHrI1gcnT1FEKC6YwfVO0RojlvfTJIXkReQ7yI/pQAl tYQPJDmLfGjp6nWTKljUO05A7pDGHjQEdrJWsj+50Wi8qd5v0iKeaYNizt8J98C9lSj1 2aWSB0ap5fXf14G5L6OGSAGgX6B0xcGZXUa8vVDO5cE3bC/BZq+2UVpCrBxxdj/gbCyo wLlg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=jVvvSlcDW1rccwafybYx7K4mL+Q61eyXYRbJr4hiI0E=; b=pACMowCpCz0hsNgaguf9Y+nOAFpIqYXLLfKioG0ykxTzfHaavm7aDt9/NlnvKQToYD BMwrD8z2qBzaIITHvYyyQZ22PqkTd9qjCnOUTBFUORpQXpxWIv2QTgO8BmaFEX7YYpR9 f3yAxSIxzUvnBDZJOHX5Ygm2GTpAAdHCdcsy78GXDDnsz9ddZhcuKNUrZeHlaoHDK8wR Pg4O+M3JRRDBQ74VDWA4xwReBr29+2vIZ6utY6gTUHBg45T2IbuyHlefA6xJjNNotXGx WBGUObZoL2wQgT42cQUn7shrUOEVaSlJe4EEeEjYNC3AVcvEjZki+xZcU76E0lH8oHP+ J4Kg== X-Gm-Message-State: AA+aEWa5irZaZuOyrJgiYRjk9/y9I91sXnughfTRqqbnCaxU9TGmBKeh q4BJzJk0U896rzw3gizLik4eaQ/b X-Google-Smtp-Source: AFSGD/VZ+ljIxOtr5OXzqt4aZMe8R+iuF1xCgMuofGsWIq9+yhE5zG4Ug/iABLSbCO5yBORcrlEBOg== X-Received: by 2002:aa7:da48:: with SMTP id w8mr14026971eds.54.1543246461315; Mon, 26 Nov 2018 07:34:21 -0800 (PST) Received: from localhost (pD9E51040.dip0.t-ipconnect.de. [217.229.16.64]) by smtp.gmail.com with ESMTPSA id c11-v6sm146882ejm.67.2018.11.26.07.34.20 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 26 Nov 2018 07:34:20 -0800 (PST) Date: Mon, 26 Nov 2018 16:34:19 +0100 From: Thierry Reding To: Jose Abreu Cc: "David S. Miller" , Giuseppe Cavallaro , Alexandre Torgue , netdev@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] net: stmmac: Move debugfs init/exit to ->probe()/->remove() Message-ID: <20181126153419.GD19710@ulmo> References: <20181123122122.18957-1-thierry.reding@gmail.com> <9c8443aa-edaa-2398-bdd8-df49f2529cb6@synopsys.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="SFyWQ0h3ruR435lw" Content-Disposition: inline In-Reply-To: <9c8443aa-edaa-2398-bdd8-df49f2529cb6@synopsys.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --SFyWQ0h3ruR435lw Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Nov 23, 2018 at 12:44:02PM +0000, Jose Abreu wrote: > On 23-11-2018 12:21, Thierry Reding wrote: > > From: Thierry Reding > > > > Setting up and tearing down debugfs is current unbalanced, as seen by > > this error during resume from suspend: > > > > [ 752.134067] dwc-eth-dwmac 2490000.ethernet eth0: ERROR failed to= create debugfs directory > > [ 752.134347] dwc-eth-dwmac 2490000.ethernet eth0: stmmac_hw_setup= : failed debugFS registration > > > > The imbalance happens because the driver creates the debugfs hierarchy > > when the device is opened and tears it down when the device is closed. > > There's little gain in that, and it could be argued that it is even > > surprising because it's not usually done for other devices. Fix the > > imbalance by moving the debugfs creation and teardown to the driver's > > ->probe() and ->remove() implementations instead. > > > > Signed-off-by: Thierry Reding > > --- > > >=20 > Did you test trying to dump "descriptors_status" file when > interface is not open ? I think that's the main reason why this > is not in probe ... Indeed, that seems to cause a hang. Still, it doesn't sound like the right things to repeatedly create and remove debugfs files just because we can't provide the contents when the device is down. How about we return an empty file or an error code instead when the interface is down? 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