Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933015AbcK1LN5 (ORCPT ); Mon, 28 Nov 2016 06:13:57 -0500 Received: from mail-wj0-f169.google.com ([209.85.210.169]:35364 "EHLO mail-wj0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932979AbcK1LNe (ORCPT ); Mon, 28 Nov 2016 06:13:34 -0500 MIME-Version: 1.0 In-Reply-To: <8359307d-5f44-3db9-aae1-eb1fe8e1141d@marvell.com> References: <3cd05a26-d340-476e-bab1-8be9d5446f47@marvell.com> <436c6925-cb0d-afe7-e3a2-384eca15ff42@marvell.com> <8359307d-5f44-3db9-aae1-eb1fe8e1141d@marvell.com> From: Ulf Hansson Date: Mon, 28 Nov 2016 12:13:31 +0100 Message-ID: Subject: Re: [PATCH 7/10] mmc: sdhci-xenon: Add support to PHYs of Marvell Xenon SDHC To: Ziji Hu Cc: Gregory CLEMENT , Adrian Hunter , "linux-mmc@vger.kernel.org" , Jason Cooper , Andrew Lunn , Sebastian Hesselbarth , Rob Herring , "devicetree@vger.kernel.org" , Thomas Petazzoni , "linux-arm-kernel@lists.infradead.org" , Jimmy Xu , Jisheng Zhang , Nadav Haklai , Ryan Gao , Doug Jones , Victor Gu , "Wei(SOCP) Liu" , Wilson Ding , Romain Perier , Yehuda Yitschak , Marcin Wojtas , Hanna Hawa , Kostya Porotchkin , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 946 Lines: 25 > > As you suggest, I replace mmc_wait_for_cmd() with mmc_send_tuning(), to > send commands for testing current sampling point set in our host PHY. > > According to my test result, it shows that mmc_send_tuning() can only support > tuning command (CMD21/CMD19). > As a result, we cannot use mmc_send_tuning() when card is in the speed modes > which doesn't support tuning, such as eMMC HS SDR, eMMC HS DRR and > SD SDR 12/SDR25/DDR50. Card will not response to tuning commands in those > speed modes. > > Could you please provide suggestions for the speed mode in which tuning is > not available? > Normally the mmc host driver shouldn't have to care about what the card supports, as that is the responsibility of the mmc core to manage. The host should only need to implement the ->execute_tuning() ops, which gets called when the card supports tuning (CMD19/21). Does it make sense? Kind regards Uffe