From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 55F5EC43219 for ; Thu, 2 May 2019 14:20:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2D8D82081C for ; Thu, 2 May 2019 14:20:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726425AbfEBOUV (ORCPT ); Thu, 2 May 2019 10:20:21 -0400 Received: from muru.com ([72.249.23.125]:47948 "EHLO muru.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726203AbfEBOUU (ORCPT ); Thu, 2 May 2019 10:20:20 -0400 Received: from atomide.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTPS id 213E9809B; Thu, 2 May 2019 14:20:37 +0000 (UTC) Date: Thu, 2 May 2019 07:20:16 -0700 From: Tony Lindgren To: Faiz Abbas Cc: linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-omap@vger.kernel.org, mark.rutland@arm.com, robh+dt@kernel.org, bcousson@baylibre.com, ulf.hansson@linaro.org, adrian.hunter@intel.com Subject: Re: [PATCH] ARM: dts: am57xx-idk: Remove support for voltage switching for SD card Message-ID: <20190502142016.GO8007@atomide.com> References: <20190502084748.22518-1-faiz_abbas@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190502084748.22518-1-faiz_abbas@ti.com> User-Agent: Mutt/1.11.4 (2019-03-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Faiz Abbas [190502 01:48]: > If UHS speed modes are enabled, a compatible SD card switches down to > 1.8V during enumeration. If after this a software reboot/crash takes > place and on-chip ROM tries to enumerate the SD card, the difference in > IO voltages (host @ 3.3V and card @ 1.8V) may end up damaging the card. > > The fix for this is to have support for power cycling the card in > hardware (with a PORz/soft-reset line causing a power cycle of the > card). Since am571x-, am572x- and am574x-idk don't have this > capability, disable voltage switching for these boards. > > The major effect of this is that the maximum supported speed > mode is now high speed(50 MHz) down from SDR104(200 MHz). This sounds a bit urgent, does it also need a stable tag or is it safe to apply against any earlier kernels? Regards, Tony > Signed-off-by: Faiz Abbas > --- > arch/arm/boot/dts/am57xx-idk-common.dtsi | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/arm/boot/dts/am57xx-idk-common.dtsi b/arch/arm/boot/dts/am57xx-idk-common.dtsi > index f7bd26458915..42e433da79ec 100644 > --- a/arch/arm/boot/dts/am57xx-idk-common.dtsi > +++ b/arch/arm/boot/dts/am57xx-idk-common.dtsi > @@ -420,6 +420,7 @@ > vqmmc-supply = <&ldo1_reg>; > bus-width = <4>; > cd-gpios = <&gpio6 27 GPIO_ACTIVE_LOW>; /* gpio 219 */ > + no-1-8-v; > }; > > &mmc2 { > -- > 2.19.2 >