From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Roese Subject: Re: [PATCH] mmc: omap_hsmmc: Add small delay after enabling power Date: Fri, 12 Sep 2014 09:26:54 +0200 Message-ID: <5412A03E.8060307@denx.de> References: <1410444665-24492-1-git-send-email-sr@denx.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mo4-p05-ob.smtp.rzone.de ([81.169.146.180]:56392 "EHLO mo4-p05-ob.smtp.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752436AbaILH0T (ORCPT ); Fri, 12 Sep 2014 03:26:19 -0400 In-Reply-To: Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Ulf Hansson Cc: linux-mmc , linux-omap , Thorsten Einsbein , Balaji T K On 11.09.2014 16:15, Ulf Hansson wrote: > On 11 September 2014 16:11, Stefan Roese wrote: >> From: Thorsten Einsbein >> >> On the TAO3530 (OMAP3530 based) we noticed that some SD cards are not >> detected reliably upon bootup (timeout). Especially the SanDisk Ultra >> 8GiB seems to be problematic here. The SanDisk Extreme also has this >> problem on this platform, but not that often. A Samsung 8 GiB type 6 >> doesn't show this problem at all. >> >> This patch now adds a short delay after enabling the power on the slot. >> With this delay all cards are detected reliably. > > Is this delay related to regulator ramp up/down time? Then I think it > maybe should be a part of the regulator code/DT. Thanks for this feedback. Yes, adding "regulator-enable-ramp-delay" to the regulator(s) solves this issue too. I wasn't aware of that one. The patch can be dropped. Thanks, Stefan