From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Date: Sun, 26 Oct 2014 00:42:30 +0200 Subject: [U-Boot] [PATCH 1/2] ARM: mxs: Enable DCDC converter for battery boot In-Reply-To: References: <1382959771-8983-1-git-send-email-marex@denx.de> Message-ID: <201410260042.30482.marex@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 On Saturday, October 25, 2014 at 11:43:05 PM, Fabio Estevam wrote: > Hi Michael, > > On Thu, Oct 23, 2014 at 5:07 AM, Michael Thalmeier > > wrote: > > Hi Marek, and Fabio > > > >> > Shouldn't this be conditional? > >> > > >> > #if defined CONFIG_MXS_ENABLE_4P2 > >> > mxs_power_enable_4p2(); > >> > #endif > >> > > >> > Then the boards that need this power supply enable > >> > CONFIG_MXS_ENABLE_4P2 in its config file. > >> > >> No, we want to start the DCDC converter unconditionally when running on > > > > battery > > > >> power to increase efficiency. > > > > I just stumbled upon this, because our board does not boot reliably any > > more with this change. > > Perhaps we have a special situation in that our board is powered via > > DCDC_BATT only by an external power source (no battery). > > > > I am currently working on creating a patch to only conditionally enabling > > this feature, or to enable it by default and have it conditionally be > > disabled for boards that are known to have problems with this. > > > > Which approach seems to be more feasible to you? > > Initially I proposed something like: > > #if defined CONFIG_MXS_ENABLE_4P2 > mxs_power_enable_4p2(); > #endif > > ,but Marek was not happy about it, so let's wait for his thoughts. Marek? Can you share the schematic of your power distribution network ? I would like to check a couple of things in there. I suspect there is a common problem with MX23 and MX28 based designs discovered by Juha and I'd like to make sure you don't suffer from it. It's OK to send the schematic off-list. Thanks! Best regards, Marek Vasut