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=-10.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 188F0C5DF60 for ; Fri, 8 Nov 2019 08:29:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E751720869 for ; Fri, 8 Nov 2019 08:29:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725975AbfKHI3L (ORCPT ); Fri, 8 Nov 2019 03:29:11 -0500 Received: from relay10.mail.gandi.net ([217.70.178.230]:43033 "EHLO relay10.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727459AbfKHI3L (ORCPT ); Fri, 8 Nov 2019 03:29:11 -0500 Received: from aptenodytes (lfbn-tou-1-421-123.w86-206.abo.wanadoo.fr [86.206.246.123]) (Authenticated sender: paul.kocialkowski@bootlin.com) by relay10.mail.gandi.net (Postfix) with ESMTPSA id 8DD8924000F; Fri, 8 Nov 2019 08:29:07 +0000 (UTC) Date: Fri, 8 Nov 2019 09:29:07 +0100 From: Paul Kocialkowski To: Russell King - ARM Linux admin Cc: Rikard Falkeborn , megous@megous.com, mark.rutland@arm.com, devicetree@vger.kernel.org, arnd@arndb.de, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, mripard@kernel.org, kishon@ti.com, linux-sunxi@googlegroups.com, robh+dt@kernel.org, tglx@linutronix.de, wens@csie.org, linux-arm-kernel@lists.infradead.org, icenowy@aosc.io Subject: Re: [PATCH] phy: allwinner: Fix GENMASK misuse Message-ID: <20191108082907.GA848664@aptenodytes> References: <20191020134229.1216351-3-megous@megous.com> <20191107204645.13739-1-rikard.falkeborn@gmail.com> <20191107233914.GW25745@shell.armlinux.org.uk> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="vtzGhvizbBRQ85DL" Content-Disposition: inline In-Reply-To: <20191107233914.GW25745@shell.armlinux.org.uk> User-Agent: Mutt/1.12.2 (2019-09-21) Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org --vtzGhvizbBRQ85DL Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Thu 07 Nov 19, 23:39, Russell King - ARM Linux admin wrote: > On Thu, Nov 07, 2019 at 09:46:45PM +0100, Rikard Falkeborn wrote: > > Arguments are supposed to be ordered high then low. > >=20 > > Signed-off-by: Rikard Falkeborn > > --- > > Spotted while trying to add compile time checks of GENMASK arguments. > > Patch has only been compile tested. >=20 > My feeling, personally, is that GENMASK() really isn't worth the pain > it causes. Can we instead get rid of this thing and just use easier > to understand and less error-prone hex masks please? One advantage it has is that is matches the order in which bit fields are usually given in datasheets, so I personally found that it makes verificati= on of fields much more straightforward and immediate. My 2 cents are that it makes sense for hardware registers. Note that I have recently introduced a SHIFT_AND_MASK_BITS macro[0] for a V= 4L2 driver, that I (and Mauro) would like to move to linux/bits.h eventually. > I don't care what anyone else says, personally I'm going to stick with > using hex masks as I find them way easier to get right first time than > a problematical opaque macro - and I really don't want the effort of > finding out that I've got the arguments wrong when I build it. It's > just _way_ easier and less error prone to use a hex mask straight off. I guess it's a matter of personal habit. [0]: https://git.linuxtv.org/media_tree.git/commit/?id=3D06eff2150d4db991ca= 236f3d05a9dc0101475aea Cheers, Paul --=20 Paul Kocialkowski, Bootlin Embedded Linux and kernel engineering https://bootlin.com --vtzGhvizbBRQ85DL Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEJZpWjZeIetVBefti3cLmz3+fv9EFAl3FJ1MACgkQ3cLmz3+f v9HD6QgAnn9qVrsChDkN0XT8+hfqz14mCavgmtmc/ATR+52Gp7hcnN1ADnJ1lK5D Fg3+wdQMcs3sxpVFFPvfr1mNlGy1/OCSUerruFRSXwj+oMdv3E5foi7Y5GdrS5G2 bUFCVGT9h5MS7TrwHoiLV7I8ZgRg2/j1MyPWH4sgjSpres2BwU+0vkxh8DvJc+Hm tJx1mzGPSFsA+RoRHdfRtSAE3iDcNibJXnct/qz6s+wtZRT/lTrAeoO2Cd6683dU FbegbM5v+j7dhZpZ7bkbgaKrCd9EAfKYpu0WP1YOUEGes00K5J4fhvk9RpA/+l9p l6BhN4YGDy1HqSdqxIzSiN4JXUNtag== =aPHq -----END PGP SIGNATURE----- --vtzGhvizbBRQ85DL--