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,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 66914C4360C for ; Fri, 4 Oct 2019 06:21:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 23C9321A4C for ; Fri, 4 Oct 2019 06:21:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="eAVNcSdY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731231AbfJDGVd (ORCPT ); Fri, 4 Oct 2019 02:21:33 -0400 Received: from mail-ua1-f68.google.com ([209.85.222.68]:39067 "EHLO mail-ua1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729648AbfJDGVd (ORCPT ); Fri, 4 Oct 2019 02:21:33 -0400 Received: by mail-ua1-f68.google.com with SMTP id b14so1706879uap.6 for ; Thu, 03 Oct 2019 23:21:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=3VA6KMsG3nx06bNmB0dVu0SsT6kYQkCPRD3KsBbwQUM=; b=eAVNcSdYZdHu2Tydt5eci09qeF80XduBLbw81dp6aYCwZtLUjglNwse6Z5WwlUx6d3 oR+GjfPOewBt/WGmeeV/AWjVXS3hd7dyK4dIDbq3pMAcoMPVAEa1wS4TVv7GLYQ8bumz 912qcbHDJCdo/mzZ9KJ+RMb8f6+dEcPqc2nkeuToFTH26lG5Oi+jNf3bIYHSQtgqEAgn SPNUB+y/mE9C7Ej2c4rhQ/W+FSf0MY4vTSKFOJ5PdcLEP/MGeF5Xrbw9eMTLhIUCgtXT E6ySS9Fv1Se7h68KEeFyn4BHxggAOw8v+yzm51iuKcfW0yDiGUwzZTereWGDwctgJk1C 4YMQ== 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=3VA6KMsG3nx06bNmB0dVu0SsT6kYQkCPRD3KsBbwQUM=; b=nIGacho6Oxql1+oMksBkeL1wJpSfYVTYUNSEIRSRnLGnxzbnTHVxgbadtPlAiO8zHI qjWtpmkmuXTRjVZmi+erNIVP33ecqCMf2UkP83p7vgswzJKj8vfc7S0+xAfvtF9sc2lG RAWSpITEneBydUuaZGLTfNeLgMfgu+MD5x9h9Ot9rWUMbk5zN+6sa3ujOJtC8cLN9OP3 LNv3xbQwmUVgDoWE0ZusnKNKrznRp4zPv2WR4FyWSoIZdDzQXTxXSUScpwTeu2IDIyD6 cXthLXI9PDu5KsnrIvIoXJHFvp4EtsDadL2ULiJXm+cg/3b2ECM/6y4xJdwYJZDimZCC rtEA== X-Gm-Message-State: APjAAAW0mnaQMAm9djCFebPe2J3iyls7wO8dt0PH36xx++TAXxMdg77d yFFX6qo7q2BLMBuuylHWXre5ziRPU4srTiA0OtQ1+Q== X-Google-Smtp-Source: APXvYqxUAWDAKSyRlKUVwmcQP5taPZrKlBCqAfpilhJXELmM3ge2ED1Kpw7lsSdHFyM2x1yd0lHq32mU/+8FdWLL6YM= X-Received: by 2002:ab0:6190:: with SMTP id h16mr5000205uan.129.1570170091738; Thu, 03 Oct 2019 23:21:31 -0700 (PDT) MIME-Version: 1.0 References: <20190905122112.29672-1-ludovic.Barre@st.com> <20190905122112.29672-2-ludovic.Barre@st.com> In-Reply-To: From: Ulf Hansson Date: Fri, 4 Oct 2019 08:20:55 +0200 Message-ID: Subject: Re: [PATCH V6 1/3] mmc: mmci: add hardware busy timeout feature To: Ludovic Barre Cc: Rob Herring , Srinivas Kandagatla , Maxime Coquelin , Alexandre Torgue , Linux ARM , Linux Kernel Mailing List , DTML , "linux-mmc@vger.kernel.org" , linux-stm32@st-md-mailman.stormreply.com 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 Fri, 4 Oct 2019 at 08:12, Ulf Hansson wrote: > > On Thu, 5 Sep 2019 at 14:21, Ludovic Barre wrote: > > > > From: Ludovic Barre > > > > In some variants, the data timer starts and decrements > > when the DPSM enters in Wait_R or Busy state > > (while data transfer or MMC_RSP_BUSY), and generates a > > data timeout error if the counter reach 0. > > > > > > -Define max_busy_timeout (in ms) according to clock. > > -Set data timer register if the command has rsp_busy flag. > > If busy_timeout is not defined by framework, the busy > > length after Data Burst is defined as 1 second > > (refer: 4.6.2.2 Write of sd specification part1 v6-0). > > How about re-phrasing this as below: > > ----- > In the stm32_sdmmc variant, the datatimer is active not only during > data transfers with the DPSM, but also while waiting for the busyend > IRQs from commands having the MMC_RSP_BUSY flag set. This leads to an > incorrect IRQ being raised to signal MCI_DATATIMEOUT error, which > simply breaks the behaviour. > > Address this by updating the datatimer value before sending a command > having the MMC_RSP_BUSY flag set. To inform the mmc core about the > maximum supported busy timeout, which also depends on the current > clock rate, set ->max_busy_timeout (in ms). > ----- > > Regarding the busy_timeout, the core should really assign it a value > for all commands having the RSP_BUSY flag set. However, I realize the > core needs to be improved to cover all these cases - and I am looking > at that, but not there yet. > > I would also suggest to use a greater value than 1s, as that seems a > bit low for the "undefined" case. Perhaps use the max_busy_timeout, > which would be nice a simple or 10s, which I think is used by some > other drivers. > > > -Add MCI_DATATIMEOUT error management in mmci_cmd_irq. > > > > Signed-off-by: Ludovic Barre > > --- > > drivers/mmc/host/mmci.c | 42 ++++++++++++++++++++++++++++++++++++----- > > drivers/mmc/host/mmci.h | 3 +++ > > 2 files changed, 40 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c > > index c37e70dbe250..c30319255dc2 100644 > > --- a/drivers/mmc/host/mmci.c > > +++ b/drivers/mmc/host/mmci.c > > @@ -1075,6 +1075,7 @@ static void > > mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c) > > { > > void __iomem *base = host->base; > > + unsigned long long clks; > > > > dev_dbg(mmc_dev(host->mmc), "op %02x arg %08x flags %08x\n", > > cmd->opcode, cmd->arg, cmd->flags); > > @@ -1097,6 +1098,16 @@ mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c) > > else > > c |= host->variant->cmdreg_srsp; > > } > > + > > + if (host->variant->busy_timeout && cmd->flags & MMC_RSP_BUSY) { > > + if (!cmd->busy_timeout) > > + cmd->busy_timeout = 1000; > > + > > + clks = (unsigned long long)cmd->busy_timeout * host->cclk; > > + do_div(clks, MSEC_PER_SEC); > > + writel_relaxed(clks, host->base + MMCIDATATIMER); > > + } > > + > > if (/*interrupt*/0) > > c |= MCI_CPSM_INTERRUPT; > > > > @@ -1201,6 +1212,7 @@ static void > > mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd, > > unsigned int status) > > { > > + u32 err_msk = MCI_CMDCRCFAIL | MCI_CMDTIMEOUT; > > void __iomem *base = host->base; > > bool sbc, busy_resp; > > > > @@ -1215,8 +1227,11 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd, > > * handling. Note that we tag on any latent IRQs postponed > > * due to waiting for busy status. > > */ > > - if (!((status|host->busy_status) & > > - (MCI_CMDCRCFAIL|MCI_CMDTIMEOUT|MCI_CMDSENT|MCI_CMDRESPEND))) > > + if (host->variant->busy_timeout && busy_resp) > > + err_msk |= MCI_DATATIMEOUT; > > + > > + if (!((status | host->busy_status) & > > + (err_msk | MCI_CMDSENT | MCI_CMDRESPEND))) > > return; > > > > /* Handle busy detection on DAT0 if the variant supports it. */ > > @@ -1235,8 +1250,7 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd, > > * while, to allow it to be set, but tests indicates that it > > * isn't needed. > > */ > > - if (!host->busy_status && > > - !(status & (MCI_CMDCRCFAIL|MCI_CMDTIMEOUT)) && > > + if (!host->busy_status && !(status & err_msk) && > > (readl(base + MMCISTATUS) & host->variant->busy_detect_flag)) { > > > > writel(readl(base + MMCIMASK0) | > > @@ -1290,6 +1304,9 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd, > > cmd->error = -ETIMEDOUT; > > } else if (status & MCI_CMDCRCFAIL && cmd->flags & MMC_RSP_CRC) { > > cmd->error = -EILSEQ; > > + } else if (host->variant->busy_timeout && busy_resp && > > + status & MCI_DATATIMEOUT) { > > + cmd->error = -ETIMEDOUT; > > It's not really clear to me what happens with the busy detection > status bit (variant->busy_detect_flag), in case a MCI_DATATIMEOUT IRQ > is raised, while also having host->busy_status set (waiting for > busyend). > > By looking at the code a few lines above this, we may do a "return;" > while waiting for the busyend IRQ even if MCI_DATATIMEOUT also is > raised, potentially losing that from being caught. Is that really > correct? A second thought. That "return;" is to manage the busyend IRQ being raised of the first edge due to broken HW. So I guess, this isn't an issue for stm32_sdmmc variant after all? I have a look at the next patches in the series.. [...] Kind regards Uffe