From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934189AbeEIIj2 (ORCPT ); Wed, 9 May 2018 04:39:28 -0400 Received: from heliosphere.sirena.org.uk ([172.104.155.198]:39288 "EHLO heliosphere.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934035AbeEIIjZ (ORCPT ); Wed, 9 May 2018 04:39:25 -0400 Date: Wed, 9 May 2018 17:39:19 +0900 From: Mark Brown To: Jorge Ramirez-Ortiz Cc: linux-kernel@vger.kernel.org Subject: Re: [RFC] regmap: allow volatile register writes with cached only read maps Message-ID: <20180509083919.GU13402@sirena.org.uk> References: <1525817169-29233-1-git-send-email-jramirez@baylibre.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="+OVWeTxrbAwQuiek" Content-Disposition: inline In-Reply-To: <1525817169-29233-1-git-send-email-jramirez@baylibre.com> X-Cookie: Advancement in position. User-Agent: Mutt/1.9.5 (2018-04-13) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --+OVWeTxrbAwQuiek Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, May 09, 2018 at 12:06:09AM +0200, Jorge Ramirez-Ortiz wrote: > Regmap only allows volatile access to registers when the client > supports both reads and writes. >=20 > This commit bypasses that limitation and enables volatile writes to > selected registers while maintaining cached accesses on all reads. For > this, the client does not need to configure the reg_read callback. I don't understand what voltile access means for write only devices. Volatile means that we don't read the cache but go direct to the hardware so if we can't read the hardware that's pretty redundant, a volatile read that goes to the cache is just a default read. --+OVWeTxrbAwQuiek Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAlrys7cACgkQJNaLcl1U h9AobQf9EBlENS1fT0Wg4oW1Rxs8fVvO+tOXm+xCt7VSxAeLVtTaVzWUKRbK7fVh XlgOcFlB36w1S+naDAs0yBhtcniGPcXgOCBobPplSthoYgycvqoFLdmDxdAHRQed cG1PUQJf9iVJy7jhTyJiC2XcmuR21Mm0ooM3baVekXRDlejnmXvlQkA4ov7kkkiu 4Dog73pdpa3SeKWPCNIHlYbwQvJ+YWVvLXvRICVUu5AfxEO+8Vz2wzQ29SZdkSX5 WpqR+mE8h2uUx+BdIb17PC2FSb2bTVwxnpXuRyB9jPD6YVevXgpSE1I1dkwQUyji XOEyQBNV+ZAUFTrK2jo7EiCJ9GfWPA== =1fX7 -----END PGP SIGNATURE----- --+OVWeTxrbAwQuiek--