From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752803AbcD0Ixa (ORCPT ); Wed, 27 Apr 2016 04:53:30 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:46723 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751550AbcD0Ix2 (ORCPT ); Wed, 27 Apr 2016 04:53:28 -0400 Message-ID: <57207E00.8070704@collabora.com> Date: Wed, 27 Apr 2016 10:53:20 +0200 From: Enric Balletbo i Serra User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.8.0 MIME-Version: 1.0 To: Jaehoon Chung , Ulf Hansson , linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RESEND PATCH v2 0/1] mmc: dw_mmc: Fix UHS tuning on some brand of cards. References: <1461657838-25484-1-git-send-email-enric.balletbo@collabora.com> <572079BE.9000006@samsung.com> In-Reply-To: <572079BE.9000006@samsung.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 27/04/16 10:35, Jaehoon Chung wrote: > On 04/26/2016 05:03 PM, Enric Balletbo i Serra wrote: >> Hi, >> >> I introduced the cover letter to give some background about this. >> >> I have been investigating a problem related to at least one specific sdcard when >> UHS-I is set. The card is not detected due the tuning phase reports a >> failure. Since the problem is only reproduced with a single model of a single >> brand of card, it is probably a card firmware issue, but the card works fine >> on my laptop. > > I think you have analyzed many case..of course..it was successful to switch voltage, right? > Maybe this patch too old..so can you remember which specific sdcard is produced? > Yes it was successful to switch voltage. The specific card is an UNIREX 16GB Class 10 SD card (Compatible with UHS-1) >> >> The first attempt to fix this was a patch sent by Doug Anderson [1], but Alim >> Akhtar found that this produced randomly a hung task on Peach-pi. I can confirm >> that it's easy to reproduce the hung task, either, with cold boots or suspend to >> ram tests. > > Yep..I have already tested and checked for this. > >> >> I tried to fix both problems (the original issue and the one introduced by the >> patch) in different ways, but I ended thinking that this second proposal is the >> most simple that solves both issues. So let's try to fix this by handling the >> response CRC error slightly differently when tuning command is happening. >> >> I tested the patch on both platforms, on exynos and on rockhip. I did lots of >> tests and at the moment the patch seems to fix the rockchip issue and don't >> hung on exynos. I'll continue testing meanwhile we discuss about it. >> >> I think the patch, at least, needs the Doug's approval (as he dig into the issue >> before) and the Tested-by Alim. So will be good if you have a slot of time to >> look a bit into this. >> >> Thanks in advance. >> Enric >> >> [1] https://lkml.org/lkml/2015/5/18/495 >> >> Changelog since v1: >> - Fix the issue found by Alim with exynos letting the data transfer >> take place only when MMC_SEND_TUNING_BLOCK is issued. >> >> Doug Anderson (1): >> mmc: dw_mmc: Wait for data transfer after response errors. >> >> drivers/mmc/host/dw_mmc.c | 27 +++++++++++++++++++++++++++ >> 1 file changed, 27 insertions(+) >> >