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,URIBL_BLOCKED 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 C0AEFC31E4B for ; Fri, 14 Jun 2019 12:04:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8E97521721 for ; Fri, 14 Jun 2019 12:04:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="G7aTMou1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727846AbfFNMEo (ORCPT ); Fri, 14 Jun 2019 08:04:44 -0400 Received: from mail-vs1-f68.google.com ([209.85.217.68]:36967 "EHLO mail-vs1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727817AbfFNMEn (ORCPT ); Fri, 14 Jun 2019 08:04:43 -0400 Received: by mail-vs1-f68.google.com with SMTP id v6so1599732vsq.4 for ; Fri, 14 Jun 2019 05:04:42 -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=wekL8YWDkqRel6lPpDwHCRj0DcIfrEA1VPjPXzU8y0w=; b=G7aTMou1vJgBraiplgcH9VZVlbYJFsAxlBbQdqVuDa3SJHcvyDthJgVqg2DS4u0IQM 1Vl+WtF9IOC5bYYcbIqpuVq3dgJzPR058qJC/EdRNB1gNr1SpRLo6iA+4IAhKNn3kWw4 um1dObJ4YBBftyVGVc6gB5YRujZpnKb1uW5SlmPHRrlCJ1KQ4OmCkUBVtesjaQ6Y/tT0 QXufDxUwKJgiVdtTVnXDZGn1Mpgat4BCjICRVvz5A5MeEc8O29p3uXt5fcnxfPqShBKg WdX86d3Qu8i8oip25NrC9qm+JfffO/xm09y+aDoJTZWgAv1wjP/yN7DnrcUab/VGHbTI bAYg== 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=wekL8YWDkqRel6lPpDwHCRj0DcIfrEA1VPjPXzU8y0w=; b=q8yZMaHJj4Awz+lf1R9SlxZnqwqnqGHurV0lx76stJkhDN3azmdM0+iz/GMC6Q37vB Wgse2gjQLUlKvh4SgTB+TXLCB4IpzjymDiQr2sn1Dr89UN2HDLeN5pgyqu6vsjtEOlR/ 8yVXmKu44SLGY1IUUwsR4vgTK9jEoSteOS2TvMtHIgsy1zNAHPN5lxnwuz4Pa0KWg8wY e9+/d/caw1gynt9n9jgkyFB+OhtCBFvEDaM3qdTAmLKOS7oTtNQs4kRZHSy44CKX1chB xpnB/T1N+Qs8Ac0SSWyBuJanCJGksQoIj8Csq+eA03j0MqqCCfjiZlbWYri3csXi7qAr Gmug== X-Gm-Message-State: APjAAAWDdO9h4tC/o0QASyjG72jypS/BGBo1nzaNlqWAdjym3b+dz2fK McmLrVb5W4V/5uDg33bcLYBKVf62DZhI/syFEmZa4A== X-Google-Smtp-Source: APXvYqzyYPyYu3NhlneNtUy4uQw7vXiO9xEyqIq8cxSgVVuv4L3wQ/rXvq7FFDRacsSyvGtTRS40uoD0WBeOCwmNVlo= X-Received: by 2002:a67:ee16:: with SMTP id f22mr3486750vsp.191.1560513881577; Fri, 14 Jun 2019 05:04:41 -0700 (PDT) MIME-Version: 1.0 References: <20190613234153.59309-1-dianders@chromium.org> <20190613234153.59309-3-dianders@chromium.org> In-Reply-To: <20190613234153.59309-3-dianders@chromium.org> From: Ulf Hansson Date: Fri, 14 Jun 2019 14:04:05 +0200 Message-ID: Subject: Re: [PATCH v4 2/5] mmc: core: API to temporarily disable retuning for SDIO CRC errors To: Douglas Anderson Cc: Kalle Valo , Adrian Hunter , Arend van Spriel , brcm80211-dev-list.pdl@broadcom.com, "open list:ARM/Rockchip SoC..." , Double Lo , Brian Norris , linux-wireless , Naveen Gupta , Madhan Mohan R , Matthias Kaehlcke , Wright Feng , Chi-Hsien Lin , netdev@vger.kernel.org, brcm80211-dev-list@cypress.com, Jiong Wu , Ritesh Harjani , Allison Randal , "linux-mmc@vger.kernel.org" , Linux Kernel Mailing List , Thomas Gleixner , Greg Kroah-Hartman , Shawn Lin , Wolfram Sang , Avri Altman Content-Type: text/plain; charset="UTF-8" Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org On Fri, 14 Jun 2019 at 01:42, Douglas Anderson wrote: > > Normally when the MMC core sees an "-EILSEQ" error returned by a host > controller then it will trigger a retuning of the card. This is > generally a good idea. > > However, if a command is expected to sometimes cause transfer errors > then these transfer errors shouldn't cause a re-tuning. This > re-tuning will be a needless waste of time. One example case where a > transfer is expected to cause errors is when transitioning between > idle (sometimes referred to as "sleep" in Broadcom code) and active > state on certain Broadcom WiFi SDIO cards. Specifically if the card > was already transitioning between states when the command was sent it > could cause an error on the SDIO bus. > > Let's add an API that the SDIO function drivers can call that will > temporarily disable the auto-tuning functionality. Then we can add a > call to this in the Broadcom WiFi driver and any other driver that > might have similar needs. > > NOTE: this makes the assumption that the card is already tuned well > enough that it's OK to disable the auto-retuning during one of these > error-prone situations. Presumably the driver code performing the > error-prone transfer knows how to recover / retry from errors. ...and > after we can get back to a state where transfers are no longer > error-prone then we can enable the auto-retuning again. If we truly > find ourselves in a case where the card needs to be retuned sometimes > to handle one of these error-prone transfers then we can always try a > few transfers first without auto-retuning and then re-try with > auto-retuning if the first few fail. > > Without this change on rk3288-veyron-minnie I periodically see this in > the logs of a machine just sitting there idle: > dwmmc_rockchip ff0d0000.dwmmc: Successfully tuned phase to XYZ > > Fixes: bd11e8bd03ca ("mmc: core: Flag re-tuning is needed on CRC errors") > Signed-off-by: Douglas Anderson > --- > > Changes in v4: > - Moved to SDIO API only (Adrian, Ulf). > - Renamed to make it less generic, now retune_crc_disable (Ulf). > - Function header makes it clear host must be claimed (Ulf). > - No more WARN_ON (Ulf). > > Changes in v3: > - Took out the spinlock since I believe this is all in one context. > > Changes in v2: > - Updated commit message to clarify based on discussion of v1. > > drivers/mmc/core/core.c | 5 +++-- > drivers/mmc/core/sdio_io.c | 36 +++++++++++++++++++++++++++++++++++ > include/linux/mmc/core.h | 2 ++ > include/linux/mmc/host.h | 1 + > include/linux/mmc/sdio_func.h | 3 +++ > 5 files changed, 45 insertions(+), 2 deletions(-) > > diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c > index 6db36dc870b5..9020cb2490f7 100644 > --- a/drivers/mmc/core/core.c > +++ b/drivers/mmc/core/core.c > @@ -144,8 +144,9 @@ void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq) > int err = cmd->error; > > /* Flag re-tuning needed on CRC errors */ > - if ((cmd->opcode != MMC_SEND_TUNING_BLOCK && > - cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200) && > + if (cmd->opcode != MMC_SEND_TUNING_BLOCK && > + cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200 && > + !host->retune_crc_disable && > (err == -EILSEQ || (mrq->sbc && mrq->sbc->error == -EILSEQ) || > (mrq->data && mrq->data->error == -EILSEQ) || > (mrq->stop && mrq->stop->error == -EILSEQ))) > diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c > index f79f0b0caab8..f822a9630b0e 100644 > --- a/drivers/mmc/core/sdio_io.c > +++ b/drivers/mmc/core/sdio_io.c > @@ -734,3 +734,39 @@ int sdio_set_host_pm_flags(struct sdio_func *func, mmc_pm_flag_t flags) > return 0; > } > EXPORT_SYMBOL_GPL(sdio_set_host_pm_flags); > + > +/** > + * sdio_retune_crc_disable - temporarily disable retuning on CRC errors > + * @func: SDIO function attached to host > + * > + * If the SDIO card is known to be in a state where it might produce > + * CRC errors on the bus in response to commands (like if we know it is > + * transitioning between power states), an SDIO function driver can > + * call this function to temporarily disable the SD/MMC core behavior of > + * triggering an automatic retuning. > + * > + * This function should be called while the host is claimed and the host > + * should remain claimed until sdio_retune_crc_enable() is called. > + * Specifically, the expected sequence of calls is: > + * - sdio_claim_host() > + * - sdio_retune_crc_disable() > + * - some number of calls like sdio_writeb() and sdio_readb() sdio_retune_crc_enable() > + * - sdio_release_host() > + */ > +void sdio_retune_crc_disable(struct sdio_func *func) > +{ > + func->card->host->retune_crc_disable = true; > +} > +EXPORT_SYMBOL_GPL(sdio_retune_crc_disable); > + > +/** > + * sdio_retune_crc_enable - reneable retuning on CRC errors /s/reneable/re-enable > + * @func: SDIO function attached to host > + * > + * This is the compement to sdio_retune_crc_disable(). > + */ > +void sdio_retune_crc_enable(struct sdio_func *func) > +{ > + func->card->host->retune_crc_disable = false; > +} > +EXPORT_SYMBOL_GPL(sdio_retune_crc_enable); > diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h > index 134a6483347a..02a13abf0cda 100644 > --- a/include/linux/mmc/core.h > +++ b/include/linux/mmc/core.h > @@ -178,6 +178,8 @@ int mmc_wait_for_cmd(struct mmc_host *host, struct mmc_command *cmd, > > int mmc_hw_reset(struct mmc_host *host); > int mmc_sw_reset(struct mmc_host *host); > +void mmc_expect_errors_begin(struct mmc_host *host); > +void mmc_expect_errors_end(struct mmc_host *host); Leftovers for earlier versions. > void mmc_set_data_timeout(struct mmc_data *data, const struct mmc_card *card); > > #endif /* LINUX_MMC_CORE_H */ > diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h > index 43d0f0c496f6..ecb7972e2423 100644 > --- a/include/linux/mmc/host.h > +++ b/include/linux/mmc/host.h > @@ -398,6 +398,7 @@ struct mmc_host { > unsigned int retune_now:1; /* do re-tuning at next req */ > unsigned int retune_paused:1; /* re-tuning is temporarily disabled */ > unsigned int use_blk_mq:1; /* use blk-mq */ > + unsigned int retune_crc_disable:1; /* don't trigger retune upon crc */ > > int rescan_disable; /* disable card detection */ > int rescan_entered; /* used with nonremovable devices */ > diff --git a/include/linux/mmc/sdio_func.h b/include/linux/mmc/sdio_func.h > index e9dfdd501cd1..4820e6d09dac 100644 > --- a/include/linux/mmc/sdio_func.h > +++ b/include/linux/mmc/sdio_func.h > @@ -167,4 +167,7 @@ extern void sdio_f0_writeb(struct sdio_func *func, unsigned char b, > extern mmc_pm_flag_t sdio_get_host_pm_caps(struct sdio_func *func); > extern int sdio_set_host_pm_flags(struct sdio_func *func, mmc_pm_flag_t flags); > > +extern void sdio_retune_crc_disable(struct sdio_func *func); > +extern void sdio_retune_crc_enable(struct sdio_func *func); > + > #endif /* LINUX_MMC_SDIO_FUNC_H */ > -- > 2.22.0.rc2.383.gf4fbbf30c2-goog > Besides the minor comments, this looks good to me. Kind regards Uffe