From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Ball Subject: Re: [PATCH] mmc: core: Prevent eMMC VCC supply to be cut from late init Date: Wed, 09 May 2012 12:56:05 -0400 Message-ID: <87zk9hmgyi.fsf@laptop.org> References: <1336572926-21013-1-git-send-email-ulf.hansson@stericsson.com> <20120509155622.GE3955@opensource.wolfsonmicro.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from void.printf.net ([89.145.121.20]:37176 "EHLO void.printf.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760365Ab2EIQz7 (ORCPT ); Wed, 9 May 2012 12:55:59 -0400 In-Reply-To: <20120509155622.GE3955@opensource.wolfsonmicro.com> (Mark Brown's message of "Wed, 9 May 2012 16:56:23 +0100") Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Mark Brown Cc: Ulf Hansson , linux-mmc@vger.kernel.org, Per Forlin , Johan Rudholm , Lee Jones , Jasi Brar , Ulf Hansson Hi, On Wed, May 09 2012, Mark Brown wrote: > On Wed, May 09, 2012 at 04:15:26PM +0200, Ulf Hansson wrote: >> From: Ulf Hansson >> >> For eMMC cards that has been initialized from a bootloader, >> the VCC voltage supply must not be cut in an uncontrolled >> manner, without first sending SLEEP or POWEROFF_NOTIFY. >> >> The regulator_init_complete late initcall, may cut the VCC >> regulator if it's reference counter is zero. To be able to >> prevent the regulator from being cut, mmc_start_host, which >> should execute at device init and thus before late init, >> calls mmc_power_up. Then the host driver is able to increase >> the reference to the regulator. > > This looks like a good, simple solution - working out how we avoid extra > power ups will probably be more invasive and might not be worth the > effort for something that's boot time only. > > Reviwed-by: Mark Brown Thanks, pushed to mmc-next for 3.5. - Chris. -- Chris Ball One Laptop Per Child