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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 927F3C43219 for ; Thu, 2 May 2019 14:35:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6AC67205F4 for ; Thu, 2 May 2019 14:35:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726350AbfEBOfa (ORCPT ); Thu, 2 May 2019 10:35:30 -0400 Received: from muru.com ([72.249.23.125]:47968 "EHLO muru.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726197AbfEBOf3 (ORCPT ); Thu, 2 May 2019 10:35:29 -0400 Received: from atomide.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTPS id 501FD809B; Thu, 2 May 2019 14:35:46 +0000 (UTC) Date: Thu, 2 May 2019 07:35:25 -0700 From: Tony Lindgren To: Faiz Abbas Cc: Faiz Abbas , 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: <20190502143525.GP8007@atomide.com> References: <20190502084748.22518-1-faiz_abbas@ti.com> <20190502142016.GO8007@atomide.com> <50559611-a501-4331-c88b-5d05f6e756e9@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <50559611-a501-4331-c88b-5d05f6e756e9@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 14:30]: > Hi Tony, > > On 02/05/19 7:50 PM, Tony Lindgren wrote: > > * 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? > > > > This should be good to apply on any previous releases. OK applying both your MMC patches into fixes today. Thanks, Tony