Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754046AbdDDM1K (ORCPT ); Tue, 4 Apr 2017 08:27:10 -0400 Received: from mezzanine.sirena.org.uk ([106.187.55.193]:44834 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753094AbdDDM1H (ORCPT ); Tue, 4 Apr 2017 08:27:07 -0400 Date: Tue, 4 Apr 2017 13:26:54 +0100 From: Mark Brown To: Michael Hennerich Cc: linus.walleij@linaro.org, wsa@the-dreams.de, linux-gpio@vger.kernel.org, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org Message-ID: <20170404122654.dfhtvpcnngl3gfco@sirena.org.uk> References: <76471664-425b-c386-3ad8-efeabc2eaf7e@analog.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="nfmggrusljzsl5r2" Content-Disposition: inline In-Reply-To: <76471664-425b-c386-3ad8-efeabc2eaf7e@analog.com> X-Cookie: Do not write below this line. User-Agent: NeoMutt/20170306 (1.8.0) X-SA-Exim-Connect-IP: 2001:470:1f1d:6b5::3 X-SA-Exim-Mail-From: broonie@sirena.org.uk Subject: Re: question about concurrent regmap i2c usage X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: No (on mezzanine.sirena.org.uk); Unknown failure Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1316 Lines: 36 --nfmggrusljzsl5r2 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Tue, Apr 04, 2017 at 10:28:23AM +0200, Michael Hennerich wrote: > A question came up, regarding whether it's recommended to mix regmap_i2c and > plain i2c_smbus or direct adapter transfers. > In this specific case for the i2c MUX portion we need to avoid double locks, > and therefore use un-locked direct adapter transfers. > The same time we also implement a small gpiochip, where we would like to use > regmap to avoid some boilerplate code for the register cache. That should work fine providing nothing tries to change cached registers underneath the regmap. regmap won't be able to tell anything's changed otherwise. --nfmggrusljzsl5r2 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAljjkQ4ACgkQJNaLcl1U h9Blagf+N43SaUCaqbPTaw/fA2XY6eSW6ixMWrS1ExqyuN3VDnfoqh+hhuGi9yUL L9/OHHcrODX8+byi4WsMGeCt/7zkLx3eo4S9SpEYoe8zheHOvl8Y1SeqfizBgYBR woS+lUqT/ae6yIg95/0zhYfK6PkEaQyU2vU8tx7/ahfyy3GfHTvKSeljcf0H1Zbu VhbA0KpSZjFjlDe0fVSzKi4i5UQO2DTC/XEyWtYB6/FAWY56kpWuQdSyf5MTLfFR WT8VC07ntp73rQ1zcGYjc22raYvjrTDff6vjn4b6ma3dZienkgJ6WIEYP6F10CPV dT86b5fYadl8bdd6Fewc6/5/Fuegag== =mLk+ -----END PGP SIGNATURE----- --nfmggrusljzsl5r2--