From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefano Babic Date: Wed, 20 Aug 2014 12:30:37 +0200 Subject: [U-Boot] [PATCH v2] mxs: fixed battery boot on imx233-olinuxino-micro In-Reply-To: <201406190912.52288.marex@denx.de> References: <1400637715-24117-1-git-send-email-peter.schumann@jeepxj.de> <53A06635.9070409@denx.de> <53A1D7A1.5010603@jeepxj.de> <201406190912.52288.marex@denx.de> Message-ID: <53F478CD.8040305@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Peter, hi Marek, On 19/06/2014 09:12, Marek Vasut wrote: > On Wednesday, June 18, 2014 at 08:17:05 PM, Peter Schumann wrote: >> Am 17.06.2014 18:00, schrieb Stefano Babic: >>> Hi peter, >>> ... >>> On 17/06/2014 00:19, Marek Vasut wrote: >>> Agree. Reason is that this change is for all boards, and without a >>> proper testing I will avoid to merge it in the release. >>> >>> Best regards, >>> Stefano Babic >> >> Hi Stefano, >> >> I've only the imx233 olimex board for testing. The DOUBLE_FETS switch in >> HW_POWER_MINPWR is some thing were maybe problems emerge. >> >> I have very little load on the powerrails (imx233 + DRAM), so maybe with >> more current demand DOUBLE_FETS is working OK and even more may require >> it to be set. > > If that was the case, the problem would manifest even when _not_ booting from > battery-only supply, correct? > >> The DOUBLE_FETS and HALF_FETS switches control the switching MOSFET size >> in the DCDC Converter. My assumption is that if we have a to big FET >> setting and to low current demand we trigger some failsafe mechanism. >> Because the required "on time" of the FET is smaller than the minimum >> possible "on time" of then DCDC FET control logic. >> >> I don't have an easy way to test this assumption without an adjustable >> load. >> >> The other change regarding mxs_power_enable_4p2() should be relatively >> safe to apply. > > This breaks booting from battery on MX28 for some reason. The DC converter is > not enabled at that point. As I have not (yet) forgotten this patch: current status is that mx28 is broken after applying this patch. I set the status as "Changes requested" and it will be not applied. Best regards, Stefano Babic -- ===================================================================== DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sbabic at denx.de =====================================================================