From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: [PATCH] ARM: dts: exynos: Fix invalid maximum voltage for buck9 supplying SD card Date: Thu, 24 Mar 2016 11:02:06 +0000 Message-ID: <20160324110206.GT2566@sirena.org.uk> References: <1458807125-13580-1-git-send-email-k.kozlowski@samsung.com> <20160324095332.GS2566@sirena.org.uk> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="aWqLLCFKF5W9Ovgk" Return-path: Received: from mezzanine.sirena.org.uk ([106.187.55.193]:33728 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755204AbcCXLC2 (ORCPT ); Thu, 24 Mar 2016 07:02:28 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Krzysztof Kozlowski Cc: Kukjin Kim , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org, Ulf Hansson , Ivaylo Dimitrov --aWqLLCFKF5W9Ovgk Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Thu, Mar 24, 2016 at 07:25:35PM +0900, Krzysztof Kozlowski wrote: > On Thu, Mar 24, 2016 at 6:53 PM, Mark Brown wrote: > > Why does this regulator even have voltage constraints configured? Is > > there any intention that it should ever be varied at runtime? > Good question. I was also wondering that, if tetting it by 5 mV lower > causes failure, then the constraints are actually fixed at 3.755 V. I > do not know the answer. Boards schematics do not specify the > requirement here, datasheet for PMIC says default value of 3.4V. Heh, For some reason people seem to frequently want to put the maximum voltage range for the regulator into the constraints even though that is almost certainly broken and generally nonsensical. > maybe the regulator driver is missing proper starting value for 'vsel' > (datasheet says values in register start from 0x40 -> 3 V). Something > looks wrong here... It's possible it's just broken and has never been tested. --aWqLLCFKF5W9Ovgk Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBCAAGBQJW88ktAAoJECTWi3JdVIfQOQoH/iCTkVsV2hkFwx94EST0UrQr FVw0+GHiO8SDtvjTNDC/c4+3gurlUfr2YD7hTzLJYrAtClh8VdbZSzES2DaguGXr cXk6rejnNQ5MwrGiYY478bTMTu7RwDdy/50DGOWm4zhlmsMH/HkVPfi5zRuPSpyj XYnwaPqEttOcnHdM8W/coaKZ59/UsZUSaT/xt0Ykr/7DDvDpTkIZs+EM2IaB7Zdy s9m0HRus/3yEU8puXnb4o8oQ3V4olyC7cdjhZJRImkLBJsCYcp/9zBdwqhnOCghe MRHTbnbmTeXCjZFAhywVWBMfCufs2c1711DW+Lx0RAY3r+5VTPXvuzzSKjMlvv8= =gX4j -----END PGP SIGNATURE----- --aWqLLCFKF5W9Ovgk--