From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joakim Tjernlund Subject: Initial signal voltage ? Date: Mon, 10 Aug 2015 16:50:38 +0000 Message-ID: <1439225438.3120.94.camel@transmode.se> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Return-path: Received: from smtp.transmode.se ([31.15.61.139]:50324 "EHLO smtp.transmode.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753102AbbHJQul convert rfc822-to-8bit (ORCPT ); Mon, 10 Aug 2015 12:50:41 -0400 Received: from exch1.transmode.se (exch1.transmode.se [192.168.201.16]) by smtp.transmode.se (Postfix) with ESMTP id 49A661186FB8 for ; Mon, 10 Aug 2015 18:50:39 +0200 (CEST) Content-Language: en-US Content-ID: Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: "linux-mmc@vger.kernel.org" in mmc_power_up() we have: /* Try to set signal voltage to 3.3V but fall back to 1.8v or 1.2v */ if (__mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_330) == 0) dev_err(mmc_dev(host), "Initial signal voltage of 3.3v\n"); else if (__mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180) == 0) dev_err(mmc_dev(host), "Initial signal voltage of 1.8v\n"); else if (__mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120) == 0) dev_err(mmc_dev(host), "Initial signal voltage of 1.2v\n"); Here one jut brutally tries to set the initial power to 3.3 but nowhere in general code there is a check if the controller can handle this w.r.t HOST CAPS. Where should this check be performed, I am guessing either here or in sdhci? This is all new to me so I am just throwing this out there Jocke