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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 B9F07C76186 for ; Tue, 23 Jul 2019 03:21:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8630C21738 for ; Tue, 23 Jul 2019 03:21:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="GUadnbS6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730369AbfGWDVn (ORCPT ); Mon, 22 Jul 2019 23:21:43 -0400 Received: from mail-wr1-f66.google.com ([209.85.221.66]:46452 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726167AbfGWDVm (ORCPT ); Mon, 22 Jul 2019 23:21:42 -0400 Received: by mail-wr1-f66.google.com with SMTP id z1so41419813wru.13; Mon, 22 Jul 2019 20:21:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Y3d4DOmXlkymFoiXcebxZGUUkG35ygxN6FhpdOM4tcw=; b=GUadnbS60UOnLG7QbjHT0gTNgfshYyzFlvGI+lhUahrLLSH2l5POvnsSdlEQ42JpwN 1wJr6Kk/J+WwAD6LSd1XbRKWUuEtgUjVevS6iGNH7QLjWm/pgYk13cUro5uDYPTPSyHg wFGEY7Hivl2kXRNYGYBdw5vcX6v/uvjlQ2+BzFYcF0eru51EW4Tm9dvWh6uPcudW1Uil SscEvWFZfBrkGId/hyUdl2emwc9AWgyZym5DvY1Yft+J7RxouyqXdKs2dvQKiGVloq60 hagxibZYjGeUpnUqUGknCmO78qUplO+4xt8pcfFgRgTbAs73oQsiaJN6EFgr72opYBJy FyPg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Y3d4DOmXlkymFoiXcebxZGUUkG35ygxN6FhpdOM4tcw=; b=YLoFS8x3PydKHVr5H7hh4hOeJ8xzpFsAaBP/XXRNlitYweYQwk6tgQyD9QgjQ3kSbH VHP/Rlrr/y9PEkU6ot1HRN6D80GUJKrJ7l+Ax0hUaMSCGYEa1L/SgPMUTe98JWXVDRqD BGNoURcTy3w4VQe9Vc5BZUBBNTvr35dPk9nwPq+KhLB19/BHPcrOtiXFcGZmxYuJgm/2 WbcJTOhiPlgFfE+Yz5nYDyVc7wyNs5+V8hFKZWNyQ/22n6t05/A+sEm/DZpJg0sHQJeO Ah+rmh/XSbNpqJHUvoFM1nAYHj+capaa199mifeXvD+W0pGaSFT8NTFodPF/ehn86CyZ POYA== X-Gm-Message-State: APjAAAW76A9HWCSbPwoEDPhlCZbgRgW/+ATj4PwfHQjUmGBGW2zOappB rUw3oDBNXoFDoEXkapDCdPhlCaR3oe9p2555Sqs= X-Google-Smtp-Source: APXvYqygKMZPmLXYU5aPZEoLbXkTYJG3b0I8FeQ90WNmNse6STW6wf+JbojI31z1cW+S7M7hHXUaMKVx4y6UoXENauw= X-Received: by 2002:a5d:6389:: with SMTP id p9mr50035409wru.297.1563852099949; Mon, 22 Jul 2019 20:21:39 -0700 (PDT) MIME-Version: 1.0 References: <89c3ef495c367d58ca3abe99a1f82c48f8c08705.1563274904.git.baolin.wang@linaro.org> In-Reply-To: From: Chunyan Zhang Date: Tue, 23 Jul 2019 11:21:03 +0800 Message-ID: Subject: Re: [PATCH v4] mmc: host: sdhci-sprd: Fix the incorrect soft reset operation when runtime resuming To: Baolin Wang Cc: Ulf Hansson , Adrian Hunter , Orson Zhai , Vincent Guittot , "linux-mmc@vger.kernel.org" , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 23 Jul 2019 at 11:05, Baolin Wang wrote: > > Hi Ulf, > > On Mon, 22 Jul 2019 at 19:54, Ulf Hansson wrote: > > > > On Wed, 17 Jul 2019 at 04:29, Baolin Wang wrote: > > > > > > In sdhci_runtime_resume_host() function, we will always do software reset > > > for all, which will cause Spreadtrum host controller work abnormally after > > > resuming. > > > > What does "software reset for all" means? > > The SD host controller specification defines 3 types software reset: > software reset for data line, software reset for command line and > software reset for all. > Software reset for all means this reset affects the entire Host > controller except for the card detection circuit. > > > > > > > > > Thus for Spreadtrum platform that will not power down the SD/eMMC card during > > > runtime suspend, we should not do software reset for all. > > > > Normally, sdhci hosts that enters runtime suspend doesn't power off > > the card (there are some exceptions like PCI variants). > > Yes, same as our controller. > > > > > So, what's so special here and how does the reset come into play? I > > don't see sdhci doing a reset in sdhci_runtime_suspend|resume_host() > > and nor doesn the callback from the sdhci-sprd.c variant doing it. > > In sdhci_runtime_resume_host(), it will issue sdhci_init(host, 0) to > issue software reset for all. > > > > > > To fix this > > > issue, adding a specific reset operation that adds one condition to validate > > > the power mode to decide if we can do software reset for all or just reset > > > command and data lines. > > > > > > Signed-off-by: Baolin Wang > > > --- > > > Changess from v3: > > > - Use ios.power_mode to validate if the card is power down or not. > > > > > > Changes from v2: > > > - Simplify the sdhci_sprd_reset() by issuing sdhci_reset(). > > > > > > Changes from v1: > > > - Add a specific reset operation instead of changing the core to avoid > > > affecting other hardware. > > > --- > > > drivers/mmc/host/sdhci-sprd.c | 19 ++++++++++++++++++- > > > 1 file changed, 18 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/mmc/host/sdhci-sprd.c b/drivers/mmc/host/sdhci-sprd.c > > > index 603a5d9..94f9726 100644 > > > --- a/drivers/mmc/host/sdhci-sprd.c > > > +++ b/drivers/mmc/host/sdhci-sprd.c > > > @@ -373,6 +373,23 @@ static unsigned int sdhci_sprd_get_max_timeout_count(struct sdhci_host *host) > > > return 1 << 31; > > > } > > > > > > +static void sdhci_sprd_reset(struct sdhci_host *host, u8 mask) > > > +{ > > > + struct mmc_host *mmc = host->mmc; > > > + > > > + /* > > > + * When try to reset controller after runtime suspend, we should not > > > + * reset for all if the SD/eMMC card is not power down, just reset > > > + * command and data lines instead. Otherwise will meet some strange > > > + * behaviors for Spreadtrum host controller. > > > + */ > > > + if (host->runtime_suspended && (mask & SDHCI_RESET_ALL) && > > > + mmc->ios.power_mode == MMC_POWER_ON) > > > + mask = SDHCI_RESET_CMD | SDHCI_RESET_DATA; > > > > Can sdhci_sprd_reset() be called when the host is runtime suspended? > > When host tries to runtime resume in sdhci_runtime_resume_host(), it > will call reset operation to do software reset. > > > That sounds like a bug to me, no? > > Since our controller will meet some strange behaviors if we do > software reset for all in sdhci_runtime_resume_host(), and try to > avoid changing the core logic of sdhci_runtime_resume_host() used by > other hardware controllers, thus I introduced a specific reset ops and > added some condition to make sure we just do software reset command > and data lines from runtime suspend state. I can make a verification on sprd's SC9863A, but that would take a little time, since I need to make sd card registered with sdhci-sprd.c first :) Thanks, Chunyan