From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751830AbcCADI5 (ORCPT ); Mon, 29 Feb 2016 22:08:57 -0500 Received: from mezzanine.sirena.org.uk ([106.187.55.193]:47560 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751353AbcCADIz (ORCPT ); Mon, 29 Feb 2016 22:08:55 -0500 Date: Tue, 1 Mar 2016 11:23:26 +0900 From: Mark Brown To: Bjorn Andersson Cc: Laxman Dewangan , robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, lgirdwood@gmail.com, bjorn.andersson@sonymobile.com, swarren@wwwdotorg.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Message-ID: <20160301022326.GC18327@sirena.org.uk> References: <1456756829-2277-1-git-send-email-ldewangan@nvidia.com> <20160229174751.GQ21240@tuxbot> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="y6IdC9+/ilDqdjNX" Content-Disposition: inline In-Reply-To: <20160229174751.GQ21240@tuxbot> X-Cookie: Adapt. Enjoy. Survive. User-Agent: Mutt/1.5.24 (2015-08-30) X-SA-Exim-Connect-IP: 106.188.128.40 X-SA-Exim-Mail-From: broonie@sirena.org.uk Subject: Re: [PATCH 1/2] regulator: DT: Add support to scale ramp delay based on platform behavior 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 --y6IdC9+/ilDqdjNX Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Mon, Feb 29, 2016 at 09:47:51AM -0800, Bjorn Andersson wrote: > On Mon 29 Feb 06:40 PST 2016, Laxman Dewangan wrote: > > It is observed that voltage change in given rail affected by the load > > and the capacitor in the rail. This may cause the slow ramp in voltage > > against what PMIC has programmed. > The regulator-ramp-delay is a variable you can tweak on a board basis, > so I'm not sure what benefit it gives to be able to add a scaling > factor to this. > In my experience your HW engineer will say "you have to wait X ms", not > "you have to wait 125% of X ms". > Can you please elaborate on why the original knob isn't sufficient? Right, this definitely feels like the wrong thing is being specified here (and also like the PMIC might be going out of spec, possibly as a result of being overloaded) and that the existing board specific controls should be used. It just doesn't correspond to the way people usually talk about specs for PMICs. --y6IdC9+/ilDqdjNX Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBCAAGBQJW1P0ZAAoJECTWi3JdVIfQDy4H/jdp+euVrbkwjW7AtGOh5VQC rxNbG4HCvPVw2uLiqHxjFEB8RvaGvv6hn2GQO4hHwY9KGzJ37hwdZyLPK6ed9UQa V1FaZuQw3aHLOZ4/H9R4t5bOr9O/WZnxaQ/H6fcnR+QO66n7mvCsy4FbCJUqFTGu Cp4QcTlaF7TMoYQG29hmIFFu5S1gunxVmpp+HNn0Lw+rnGDOc+oK9AvZey5ruEM+ TzslDB3oyS2/+WrYXUfFuIeB7vGLrt9cGp4fkbZ025TZOPR969K/FJV3yOXIM9Ow o+K6gev8yvPG0qCp9BLTzySbZ3UPXL50drLSdkmcrpR3nR8oS3Z5e/UW5nZ4JfQ= =hRcQ -----END PGP SIGNATURE----- --y6IdC9+/ilDqdjNX--