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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 69368C43603 for ; Fri, 20 Dec 2019 08:10:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 469C524680 for ; Fri, 20 Dec 2019 08:10:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725965AbfLTIKb (ORCPT ); Fri, 20 Dec 2019 03:10:31 -0500 Received: from mga02.intel.com ([134.134.136.20]:58693 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725941AbfLTIKa (ORCPT ); Fri, 20 Dec 2019 03:10:30 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Dec 2019 00:10:29 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,335,1571727600"; d="scan'208";a="416461808" Received: from ahunter-desktop.fi.intel.com (HELO [10.237.72.76]) ([10.237.72.76]) by fmsmga005.fm.intel.com with ESMTP; 20 Dec 2019 00:10:28 -0800 Subject: Re: [PATCH v2] mmc: sdhci-cadence: tune multi-block read gap To: Vladimir Kondratiev , Ulf Hansson Cc: linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org References: <20191217115502.5590-1-vladimir.kondratiev@intel.com> <20191217121102.11213-1-vladimir.kondratiev@intel.com> From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Message-ID: <6b59ee49-bbba-5cb2-36c4-e9e404af3ff5@intel.com> Date: Fri, 20 Dec 2019 10:09:36 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <20191217121102.11213-1-vladimir.kondratiev@intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org On 17/12/19 2:11 pm, Vladimir Kondratiev wrote: > Additional tuning required for multi-block read command. > Implement it accordingly to Cadence recommendation. > > 2 registers used: HRS37 and HRS38. To HRS37, SD interface mode programmed, > this selects HRS38 slot - there is separate slot for every SD interface > mode. HRS38 contains gap parameter, > it is selected by starting with gap=0 and sending multi-block read command. > gap incremented until multi-block read succeeds. > > As of now, this tuning executed for HS200 only > > Signed-off-by: Vladimir Kondratiev > --- > drivers/mmc/host/sdhci-cadence.c | 137 ++++++++++++++++++++++++++++++- > 1 file changed, 136 insertions(+), 1 deletion(-) > > diff --git a/drivers/mmc/host/sdhci-cadence.c b/drivers/mmc/host/sdhci-cadence.c > index ae0ec27dd7cc..d0bed1932b6c 100644 > --- a/drivers/mmc/host/sdhci-cadence.c > +++ b/drivers/mmc/host/sdhci-cadence.c > @@ -34,6 +34,23 @@ > #define SDHCI_CDNS_HRS06_MODE_MMC_HS400 0x5 > #define SDHCI_CDNS_HRS06_MODE_MMC_HS400ES 0x6 > > +/* Read block gap */ > +#define SDHCI_CDNS_HRS37 0x94 /* interface mode select */ > +#define SDHCI_CDNS_HRS37_MODE_DS 0x0 > +#define SDHCI_CDNS_HRS37_MODE_HS 0x1 > +#define SDHCI_CDNS_HRS37_MODE_UDS_SDR12 0x8 > +#define SDHCI_CDNS_HRS37_MODE_UDS_SDR25 0x9 > +#define SDHCI_CDNS_HRS37_MODE_UDS_SDR50 0xa > +#define SDHCI_CDNS_HRS37_MODE_UDS_SDR104 0xb > +#define SDHCI_CDNS_HRS37_MODE_UDS_DDR50 0xc > +#define SDHCI_CDNS_HRS37_MODE_MMC_LEGACY 0x20 > +#define SDHCI_CDNS_HRS37_MODE_MMC_SDR 0x21 > +#define SDHCI_CDNS_HRS37_MODE_MMC_DDR 0x22 > +#define SDHCI_CDNS_HRS37_MODE_MMC_HS200 0x23 > +#define SDHCI_CDNS_HRS37_MODE_MMC_HS400 0x24 > +#define SDHCI_CDNS_HRS37_MODE_MMC_HS400ES 0x25 > +#define SDHCI_CDNS_HRS38 0x98 /* Read block gap coefficient */ > +#define SDHCI_CDNS_HRS38_BLKGAP_MAX 0xf > /* SRS - Slot Register Set (SDHCI-compatible) */ > #define SDHCI_CDNS_SRS_BASE 0x200 > > @@ -272,6 +289,118 @@ static int sdhci_cdns_set_tune_val(struct sdhci_host *host, unsigned int val) > return 0; > } > > +/** > + * mmc_send_mb_read() - send multi-block read command > + * @host: MMC host > + * > + * Sends multi-block read command, CMD23/CMD18/CMD12, ignore read data > + * > + * Return: error code > + */ > +static int mmc_send_mb_read(struct mmc_host *host) > +{ > + const int blksz = 512; > + const int blocks = 32; > + struct scatterlist sg; > + struct mmc_command sbc = { > + .opcode = MMC_SET_BLOCK_COUNT, > + .arg = blocks, > + .flags = MMC_RSP_R1 | MMC_CMD_AC, > + }; > + struct mmc_command cmd = { > + .opcode = MMC_READ_MULTIPLE_BLOCK, > + .arg = 0, > + .flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC, > + }; > + struct mmc_command stop = { > + .opcode = MMC_STOP_TRANSMISSION, > + .arg = 0, > + .flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC, > + }; > + struct mmc_data data = { > + .flags = MMC_DATA_READ, > + .blksz = blksz, > + .blocks = blocks, > + .blk_addr = 0, > + .timeout_ns = 800000000, /* 800ms */ > + .timeout_clks = 1000, > + .sg = &sg, > + .sg_len = 1, > + }; > + struct mmc_request mrq = { > + .sbc = &sbc, > + .cmd = &cmd, > + .data = &data, > + .stop = &stop, > + }; > + int size = blksz * blocks, err = 0; > + u8 *data_buf; > + > + data_buf = kzalloc(size, GFP_KERNEL); > + if (!data_buf) > + return -ENOMEM; > + > + sg_init_one(&sg, data_buf, size); > + > + mmc_wait_for_req(host, &mrq); This is a bit weird. Why can't a regular tuning command be used? > + > + if (cmd.error) { > + err = cmd.error; > + goto out; > + } > + > + if (data.error) { > + err = data.error; > + goto out; > + } > + > +out: > + kfree(data_buf); > + return err; > +} > + > +/** > + * sdhci_cdns_tune_blkgap() - tune multi-block read gap > + * @mmc: MMC host > + * > + * Tune delay used in multi block read. To do so, > + * try sending multi-block read command with incremented gap, unless > + * it succeeds. > + * > + * Return: error code > + */ > +static int sdhci_cdns_tune_blkgap(struct mmc_host *mmc) > +{ > + struct sdhci_host *host = mmc_priv(mmc); > + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); > + struct sdhci_cdns_priv *priv = sdhci_pltfm_priv(pltfm_host); > + void __iomem *hrs37_reg = priv->hrs_addr + SDHCI_CDNS_HRS37; > + void __iomem *hrs38_reg = priv->hrs_addr + SDHCI_CDNS_HRS38; > + bool tuned = false; > + u8 gap; > + u8 hrs37_mode; > + > + switch (host->timing) { > + case MMC_TIMING_MMC_HS200: > + hrs37_mode = SDHCI_CDNS_HRS37_MODE_MMC_HS200; > + break; > + default: > + return 0; /* no tuning in this mode */ > + } > + > + writel(hrs37_mode, hrs37_reg); > + > + for (gap = 0; gap <= SDHCI_CDNS_HRS38_BLKGAP_MAX; gap++) { > + writel(gap, hrs38_reg); > + tuned = !mmc_send_mb_read(mmc); > + if (tuned) > + break; > + } > + dev_dbg(mmc_dev(mmc), "read block gap tune %s, gap %d\n", > + tuned ? "OK" : "failed", gap); > + return tuned ? 0 : -EIO; > +} > + > static int sdhci_cdns_execute_tuning(struct mmc_host *mmc, u32 opcode) > { > struct sdhci_host *host = mmc_priv(mmc); > @@ -279,6 +408,7 @@ static int sdhci_cdns_execute_tuning(struct mmc_host *mmc, u32 opcode) > int max_streak = 0; > int end_of_streak = 0; > int i; > + int ret; > > /* > * This handler only implements the eMMC tuning that is specific to > @@ -308,7 +438,12 @@ static int sdhci_cdns_execute_tuning(struct mmc_host *mmc, u32 opcode) > return -EIO; > } > > - return sdhci_cdns_set_tune_val(host, end_of_streak - max_streak / 2); > + ret = sdhci_cdns_set_tune_val(host, end_of_streak - max_streak / 2); > + > + if (!ret) > + ret = sdhci_cdns_tune_blkgap(mmc); > + > + return ret; > } > > static void sdhci_cdns_hs400_enhanced_strobe(struct mmc_host *mmc, >