From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751609AbaL3RFT (ORCPT ); Tue, 30 Dec 2014 12:05:19 -0500 Received: from mezzanine.sirena.org.uk ([106.187.55.193]:56012 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751303AbaL3RFR (ORCPT ); Tue, 30 Dec 2014 12:05:17 -0500 Date: Tue, 30 Dec 2014 17:04:45 +0000 From: Mark Brown To: Chris Zhong Cc: heiko@sntech.de, dianders@chromium.org, linux-rockchip@lists.infradead.org, Liam Girdwood , linux-kernel@vger.kernel.org Message-ID: <20141230170445.GP17800@sirena.org.uk> References: <1418612879-16094-1-git-send-email-zyw@rock-chips.com> <1418612879-16094-3-git-send-email-zyw@rock-chips.com> <20141229172555.GE17800@sirena.org.uk> <54A216E2.4090504@rock-chips.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="vpcjF8Qude6+yKQm" Content-Disposition: inline In-Reply-To: <54A216E2.4090504@rock-chips.com> X-Cookie: You have no real enemies. User-Agent: Mutt/1.5.23 (2014-03-12) X-SA-Exim-Connect-IP: 86.128.155.20 X-SA-Exim-Mail-From: broonie@sirena.org.uk Subject: Re: [PATCH v3 2/2] regulator: rk808: add dvs support X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: Yes (on mezzanine.sirena.org.uk) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --vpcjF8Qude6+yKQm Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Tue, Dec 30, 2014 at 11:07:14AM +0800, Chris Zhong wrote: > On 12/30/2014 01:25 AM, Mark Brown wrote: > >So, this seems a bit odd. What we appear to be doing here is > >alternating between the two different voltage setting registers which is > >all well and good but makes me wonder why we're bothering - it's a bit > >more work than just sticking with one. We do get... > you mean check the old_selector and selector? I think > _regulator_do_set_voltage have done it. No, I mean that we may as well just always write to the same register and save a bunch of code. > >...this but unless the voltage typically ramps much faster than spec > >it's never clear to me that we're actually winning by polling the pin > >instead of just dead reckoning the time, it's more work for the CPU to > >poll the GPIO than to sleep after all. > Actually, it's slower than spec, so I think getting this dvsok pin state > is safer than delay. Well, that suggests that the spec is wrong which ought to be fixed anyway oughtn't it? Or are you saying that the delay is inconsistent as well as slower than advertised? --vpcjF8Qude6+yKQm Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBAgAGBQJUotssAAoJECTWi3JdVIfQk+gH/3AwbBe0fCzP2CGNrD+HwNUl wW0ztBBkZyn5y8K8XjH8gG1mhVxKvakNTBFbfI+mA1EsC3Z3KPyyJcDSIevHXg0N JRrPqS10O2fDUrvffSEXJLZHziL8MseszzVkyKosSfcW4vMv2nBruamOFRHeC7hr 3kBhRh2JnRAPsaTA1HPUYx7Rgvgz4OCqmxfEMmWdWVgyVuxfNUvjDP39S6EYMoHg JbZwQVZ2M3DKqTcqp2GAjk20S0ILRaKEG9/Y+LnbseKuHmMdhnobRjGLzk8NlCyM l2YemLbsbIneIsbhw6C9SnDAEPKMV7P/HCE9jd4UeP3maMQ3N0jVAdkAJNZn1dQ= =ydOK -----END PGP SIGNATURE----- --vpcjF8Qude6+yKQm--