From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adrian Hunter Subject: Re: [PATCH 14/23] mmc: sdhci-esdhci-imx: disable DLL delay line settings explicitly Date: Tue, 10 May 2016 14:02:50 +0300 Message-ID: <5731BFDA.2000504@intel.com> References: <1460741387-23815-1-git-send-email-aisheng.dong@nxp.com> <1460741387-23815-15-git-send-email-aisheng.dong@nxp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mga14.intel.com ([192.55.52.115]:55772 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751063AbcEJLGp (ORCPT ); Tue, 10 May 2016 07:06:45 -0400 In-Reply-To: <1460741387-23815-15-git-send-email-aisheng.dong@nxp.com> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Dong Aisheng , linux-mmc@vger.kernel.org Cc: ulf.hansson@linaro.org, chris@printf.net, shawnguo@kernel.org, linux-arm-kernel@lists.infradead.org, haibo.chen@nxp.com, dongas86@gmail.com On 15/04/16 20:29, Dong Aisheng wrote: > From: Dong Aisheng > > Disable DLL delay line settings explicitly during driver initialization > in case ROM/uBoot had set an invalid delay. > e.g. MX6DL ROM has set the default delay line(DLLCTRL) to 0x1000021, > the uSDHC clock timing will become marginal when works on DDR mode > due to default delay and will possibly see CRC errors in case the board > is not perfectly designed on the eMMC chip layout. > > Signed-off-by: Dong Aisheng Acked-by: Adrian Hunter > --- > drivers/mmc/host/sdhci-esdhc-imx.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c > index 4c28fbb..d02db66 100644 > --- a/drivers/mmc/host/sdhci-esdhc-imx.c > +++ b/drivers/mmc/host/sdhci-esdhc-imx.c > @@ -1186,6 +1186,9 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev) > */ > writel(readl(host->ioaddr + 0x6c) | BIT(7), > host->ioaddr + 0x6c); > + > + /* disable DLL_CTRL delay line settings */ > + writel(0x0, host->ioaddr + ESDHC_DLL_CTRL); > } > > if (imx_data->socdata->flags & ESDHC_FLAG_MAN_TUNING) >