From patchwork Wed May 3 10:05:23 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Beno=C3=AEt_Th=C3=A9baudeau?= X-Patchwork-Id: 9709143 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id A679F6021C for ; Wed, 3 May 2017 10:14:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8E47B27813 for ; Wed, 3 May 2017 10:14:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8320A284E5; Wed, 3 May 2017 10:14:45 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2ED7627813 for ; Wed, 3 May 2017 10:14:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753062AbdECKOo (ORCPT ); Wed, 3 May 2017 06:14:44 -0400 Received: from authsmtp93.register.it ([195.110.122.178]:39304 "EHLO authsmtp.register.it" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752831AbdECKOf (ORCPT ); Wed, 3 May 2017 06:14:35 -0400 Received: from rad-ubuntu.home ([90.105.184.123]) by paganini37 with id Fm5T1v0212g9efN01m5iED; Wed, 03 May 2017 12:05:51 +0200 X-Rid: benoit@wsystem.com@90.105.184.123 From: =?UTF-8?q?Beno=C3=AEt=20Th=C3=A9baudeau?= To: linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org Cc: Ulf Hansson , Adrian Hunter , Fabio Estevam , joancarles , =?UTF-8?q?Eric=20B=C3=A9nard?= , Wolfram Sang , =?UTF-8?q?Beno=C3=AEt=20Th=C3=A9baudeau?= Subject: [PATCH 2/4] mmc: sdhci-esdhc-imx: Fix DAT line software reset Date: Wed, 3 May 2017 12:05:23 +0200 Message-Id: <1493805925-3644-2-git-send-email-benoit@wsystem.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1493805925-3644-1-git-send-email-benoit@wsystem.com> References: <1493805925-3644-1-git-send-email-benoit@wsystem.com> MIME-Version: 1.0 Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On i.MX25, the eSDHC DAT line software reset (SYSCTL.RSTD) unexpectedly clears at least the data transfer width (PROCTL.DTW), which then results in data CRC errors. This behavior is not documented, but it has actually been observed. Consequently, the DAT line software resets triggered by sdhci.c in case of errors caused unrecoverable errors. Fix this by making sure that the DAT line software reset does not alter the Host Control register. This behavior being undocumented, it may also be present on other i.MX SoCs, so apply this fix for the whole i.MX family. Signed-off-by: Benoît Thébaudeau Acked-by: Adrian Hunter Reviewed-by: Fabio Estevam --- drivers/mmc/host/sdhci-esdhc-imx.c | 59 ++++++++++++++++++++++++-------------- 1 file changed, 38 insertions(+), 21 deletions(-) diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c index 23d8b8a..4ee82e1 100644 --- a/drivers/mmc/host/sdhci-esdhc-imx.c +++ b/drivers/mmc/host/sdhci-esdhc-imx.c @@ -579,7 +579,7 @@ static void esdhc_writeb_le(struct sdhci_host *host, u8 val, int reg) { struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); struct pltfm_imx_data *imx_data = sdhci_pltfm_priv(pltfm_host); - u32 new_val; + u32 new_val = 0; u32 mask; switch (reg) { @@ -610,29 +610,46 @@ static void esdhc_writeb_le(struct sdhci_host *host, u8 val, int reg) esdhc_clrset_le(host, mask, new_val, reg); return; + case SDHCI_SOFTWARE_RESET: + if (val & SDHCI_RESET_DATA) + new_val = readl(host->ioaddr + SDHCI_HOST_CONTROL); + break; } esdhc_clrset_le(host, 0xff, val, reg); - /* - * The esdhc has a design violation to SDHC spec which tells - * that software reset should not affect card detection circuit. - * But esdhc clears its SYSCTL register bits [0..2] during the - * software reset. This will stop those clocks that card detection - * circuit relies on. To work around it, we turn the clocks on back - * to keep card detection circuit functional. - */ - if ((reg == SDHCI_SOFTWARE_RESET) && (val & 1)) { - esdhc_clrset_le(host, 0x7, 0x7, ESDHC_SYSTEM_CONTROL); - /* - * The reset on usdhc fails to clear MIX_CTRL register. - * Do it manually here. - */ - if (esdhc_is_usdhc(imx_data)) { - /* the tuning bits should be kept during reset */ - new_val = readl(host->ioaddr + ESDHC_MIX_CTRL); - writel(new_val & ESDHC_MIX_CTRL_TUNING_MASK, - host->ioaddr + ESDHC_MIX_CTRL); - imx_data->is_ddr = 0; + if (reg == SDHCI_SOFTWARE_RESET) { + if (val & SDHCI_RESET_ALL) { + /* + * The esdhc has a design violation to SDHC spec which + * tells that software reset should not affect card + * detection circuit. But esdhc clears its SYSCTL + * register bits [0..2] during the software reset. This + * will stop those clocks that card detection circuit + * relies on. To work around it, we turn the clocks on + * back to keep card detection circuit functional. + */ + esdhc_clrset_le(host, 0x7, 0x7, ESDHC_SYSTEM_CONTROL); + /* + * The reset on usdhc fails to clear MIX_CTRL register. + * Do it manually here. + */ + if (esdhc_is_usdhc(imx_data)) { + /* + * the tuning bits should be kept during reset + */ + new_val = readl(host->ioaddr + ESDHC_MIX_CTRL); + writel(new_val & ESDHC_MIX_CTRL_TUNING_MASK, + host->ioaddr + ESDHC_MIX_CTRL); + imx_data->is_ddr = 0; + } + } else if (val & SDHCI_RESET_DATA) { + /* + * The eSDHC DAT line software reset clears at least the + * data transfer width on i.MX25, so make sure that the + * Host Control register is unaffected. + */ + esdhc_clrset_le(host, 0xff, new_val, + SDHCI_HOST_CONTROL); } } }