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,URIBL_BLOCKED,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 ABA52C3A59E for ; Wed, 21 Aug 2019 12:30:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8AAE7206BA for ; Wed, 21 Aug 2019 12:30:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726513AbfHUMaj (ORCPT ); Wed, 21 Aug 2019 08:30:39 -0400 Received: from relay11.mail.gandi.net ([217.70.178.231]:53047 "EHLO relay11.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726371AbfHUMai (ORCPT ); Wed, 21 Aug 2019 08:30:38 -0400 Received: from localhost (lfbn-1-17395-211.w86-250.abo.wanadoo.fr [86.250.200.211]) (Authenticated sender: maxime.ripard@bootlin.com) by relay11.mail.gandi.net (Postfix) with ESMTPSA id B0B90100007; Wed, 21 Aug 2019 12:30:35 +0000 (UTC) Date: Wed, 21 Aug 2019 14:30:35 +0200 From: Maxime Ripard To: Samuel Holland Cc: Chen-Yu Tsai , Jassi Brar , Michael Turquette , Stephen Boyd , Rob Herring , Mark Rutland , Corentin Labbe , Vasily Khoruzhick , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-sunxi@googlegroups.com, linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v4 04/10] mailbox: sunxi-msgbox: Add a new mailbox driver Message-ID: <20190821123035.tl4aakijjhw3bwbk@flea> References: <20190820032311.6506-1-samuel@sholland.org> <20190820032311.6506-5-samuel@sholland.org> <20190820111825.2w55fleehrnon27u@core.my.home> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="mrpxrcur5riymvjn" Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716 Sender: linux-clk-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org --mrpxrcur5riymvjn Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Aug 20, 2019 at 08:07:53AM -0500, Samuel Holland wrote: > On 8/20/19 6:18 AM, Ond=C5=99ej Jirman wrote: > >> + reset =3D devm_reset_control_get(dev, NULL); > >> + if (IS_ERR(reset)) { > >> + ret =3D PTR_ERR(reset); > >> + dev_err(dev, "Failed to get reset control: %d\n", ret); > >> + goto err_disable_unprepare; > >> + } > >> + > >> + ret =3D reset_control_deassert(reset); > >> + if (ret) { > >> + dev_err(dev, "Failed to deassert reset: %d\n", ret); > >> + goto err_disable_unprepare; > >> + } > > > > You need to assert the reset again from now on, in error paths. devm > > will not do that for you. > > I know, and that's intentional. This same message box device is used for = ATF to > communicate with SCP firmware (on a different channel). This could be hap= pening > on a different core while Linux is running. So Linux is not allowed to de= assert > the reset. clk_disable_unprepare() is only okay because the clock is mark= ed as > critical. I agree with Ondrej that since this is clearly not the standard use of the API, this must have a big comment explaining why we're doing it this way. Maxime -- Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com --mrpxrcur5riymvjn Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRcEzekXsqa64kGDp7j7w1vZxhRxQUCXV05awAKCRDj7w1vZxhR xbIJAP9yrpmQb5VASu0xwjQKiF8z6Qkk63ohQogxkr2k66hwcAEAulMS7ROeVRrO iA0Lo17qVmuTaZnBbSFPofjTOChqgAQ= =0XW2 -----END PGP SIGNATURE----- --mrpxrcur5riymvjn--