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 83D6EC76188 for ; Mon, 3 Apr 2023 22:21:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233672AbjDCWVI (ORCPT ); Mon, 3 Apr 2023 18:21:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41272 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233653AbjDCWVE (ORCPT ); Mon, 3 Apr 2023 18:21:04 -0400 Received: from mail-yw1-x1135.google.com (mail-yw1-x1135.google.com [IPv6:2607:f8b0:4864:20::1135]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 115A44692 for ; Mon, 3 Apr 2023 15:21:00 -0700 (PDT) Received: by mail-yw1-x1135.google.com with SMTP id 00721157ae682-54601d90118so424366067b3.12 for ; Mon, 03 Apr 2023 15:20:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1680560459; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=4tpYjQoj3oN1IoUY/Iv8IxUfroJ3Fr1IgWFkmKykvfw=; b=HUCtM1lJauriEzHWd+aWCI2BC8Jq48a1ShnRUosbft5UxPct5+OFyOeCZ8yiBaH+dM XvlbZklHGWDBjrSxJb3S7WHBaMeE7TNRCfDDKyxWoJqEGj6SJpfJc2I1Sujgg0xQGq5O TGNMqh7PO8PND6u+4tHPY0CygO35y1/lzCviyFk1f9M4cN8TZZ80Xe9D+gYHrnIlCgdP 5Upf6ZvrtLzwyU4djqswhaS5ekk+mzcLx88CsIpW9dsiUuFmiwFlf6Lpvy0kLNJRINcX foDoHo94QrviD0U9ABQnD3TktIYD3+Foq2Mkohi5+T1AQtQONhCyyois8ynFG+61p7Or 6zZQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680560459; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=4tpYjQoj3oN1IoUY/Iv8IxUfroJ3Fr1IgWFkmKykvfw=; b=WUBCH77d753JH82stEWWJtPdA0cKZlJhtenbP/TK4C9LlYYsTpTO+Mog5989qAa1s4 nDRFBOZy90iRKULwSfC+Hz/gLeCvMfpwY0Nl3+XSSy0MdgxTOaOumWNHkmzCFSfasTL7 RJVgV1T966PqtSm+KmqIvd7Y36XFrZdIX/Grx2ijT1k0dSYd8+C7Y5c50cmFSIzm6MXS 70O+Cp6I2TOKpQHk6kZ03Nvzuo04ds/b44K+yO5cRJLHxKRx1JpefTQQ2krkT16M/RJe gYdBXbgrLuiqHN9e3QcVBBg1XxbJC58Q75dlFasYfdUbd2n1w/q5FuVfgBWHR59A97iL 2WKw== X-Gm-Message-State: AAQBX9cR7XmKZYFzTGDritaq+ueGl8wTnxj+363cKRliueTFejYZITPP DZeXco84s1yra0lEm8bP04KffQ== X-Google-Smtp-Source: AKy350admhROloQrgoeQCgd64bNrsFHuglHZb134fctMGzhDpYAOaPKSIb+hcRc2bKcZcNpF/uRDvA== X-Received: by 2002:a81:a00a:0:b0:541:75a3:9bc8 with SMTP id x10-20020a81a00a000000b0054175a39bc8mr434644ywg.44.1680560459064; Mon, 03 Apr 2023 15:20:59 -0700 (PDT) Received: from fedora (69-109-179-158.lightspeed.dybhfl.sbcglobal.net. [69.109.179.158]) by smtp.gmail.com with ESMTPSA id cg9-20020a05690c0a0900b00545a08184b8sm2794019ywb.72.2023.04.03.15.20.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 03 Apr 2023 15:20:58 -0700 (PDT) Date: Mon, 3 Apr 2023 18:20:56 -0400 From: William Breathitt Gray To: Mark Brown Cc: Andy Shevchenko , Linus Walleij , Bartosz Golaszewski , linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org, techsupport@winsystems.com, Paul Demetrotion , Michael Walle Subject: Re: [PATCH v5 3/3] gpio: ws16c48: Migrate to the regmap API Message-ID: References: <58531b1b2428e4d5d2ea79e721f7ef6450665280.1679845842.git.william.gray@linaro.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="50JiiM9KWQUDRx4Z" Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --50JiiM9KWQUDRx4Z Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Apr 03, 2023 at 10:12:44PM +0100, Mark Brown wrote: > On Sun, Apr 02, 2023 at 10:39:02AM -0400, William Breathitt Gray wrote: > > On Mon, Mar 27, 2023 at 02:26:37PM +0300, Andy Shevchenko wrote: > > > On Sun, Mar 26, 2023 at 12:25:59PM -0400, William Breathitt Gray wrot= e: >=20 > > > > +static const struct regmap_config ws16c48_regmap_config =3D { > > > > + .reg_bits =3D 8, > > > > + .reg_stride =3D 1, > > > > + .val_bits =3D 8, > > > > + .io_port =3D true, > > > > + .max_register =3D 0xA, > > > > + .wr_table =3D &ws16c48_wr_table, > > > > + .rd_table =3D &ws16c48_rd_table, > > > > + .volatile_table =3D &ws16c48_volatile_table, > > > > + .cache_type =3D REGCACHE_FLAT, > > > > +}; >=20 > > > Do we need regmap lock? >=20 > > We make regmap calls within an interrupt context in this driver so I > > think we need to disable the default regmap mutex locking behavior; I > > believe the current raw_spin_lock locking in this driver is enough to > > protect access. >=20 > The above doesn't configure the regmap locking so you'll have a spinlock > by default (MMIO being a fast bus). You're right, it'll be a spinlock in this case and not mutex. Unfortunately, we'll still need to change that to avoid deadlocks on -rt kernels [0]. William Breathitt Gray [0] https://lore.kernel.org/all/1466065537-82027-1-git-send-email-mika.west= erberg@linux.intel.com/ --50JiiM9KWQUDRx4Z Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEARYKAB0WIQSNN83d4NIlKPjon7a1SFbKvhIjKwUCZCtRSAAKCRC1SFbKvhIj Ky0DAP9IpyENdB034mfM5YZYx5/meDB6ZINnU28U/PqlovWaAAD9Hf4p7mhg2j/v Wxu906U2SCA8gH1bxrcyur4P5T0EHgY= =fMtc -----END PGP SIGNATURE----- --50JiiM9KWQUDRx4Z--