From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Ball Subject: Re: [PATCH 2/2] mmc: add no-1-8-v device tree flag Date: Mon, 03 Dec 2012 14:04:26 -0500 Message-ID: <8738znj6th.fsf@octavius.laptop.org> References: <20121125180255.DB8ADFAD06@dev.laptop.org> Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from void.printf.net ([89.145.121.20]:37928 "EHLO void.printf.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751396Ab2LCTEc (ORCPT ); Mon, 3 Dec 2012 14:04:32 -0500 In-Reply-To: <20121125180255.DB8ADFAD06@dev.laptop.org> (Daniel Drake's message of "Sun, 25 Nov 2012 13:02:54 -0500 (EST)") Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Daniel Drake Cc: linux-mmc@vger.kernel.org, jrudholm@gmail.com, prakity@nvidia.com, devicetree-discuss@lists.ozlabs.org Hi, On Sun, Nov 25 2012, Daniel Drake wrote: > The OLPC XO-1.75 laptop includes a SDHCI controller which is 1.8v > capable, and it truthfully reports so in its capabilities. This > alternate voltage is used for driving new "UHS-I" SD cards at their > full speed. > > However, what the controller doesn't know is that the motherboard > physically doesn't have a 1.8v supply available, so attempting to > switch to the 1.8v level will result in a situation that cannot be > recovered from without physically replugging the SD card. > > Add a device tree flag that can be used on systems like these, > and hook it up to the equivalent SDHCI quirk. > > Signed-off-by: Daniel Drake Thanks, pushed to mmc-next for 3.8. - Chris. -- Chris Ball One Laptop Per Child