Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <20210926092835.146449-1-zhang.lyra@gmail.com>
In-Reply-To: <20210926092835.146449-1-zhang.lyra@gmail.com>
From:   Ulf Hansson <ulf.hansson@linaro.org>
Date:   Tue, 28 Sep 2021 00:32:14 +0200
Message-ID: <CAPDyKFrMEs-9fUHWPVofR0VG45ywXPLb4Hf5tg5kMjvOwR+KGA@mail.gmail.com>
Subject: Re: [PATCH v2] mmc: sdhci-sprd: Wait until DLL locked after being configured
To:     Chunyan Zhang <zhang.lyra@gmail.com>
Cc:     Adrian Hunter <adrian.hunter@intel.com>,
        linux-mmc <linux-mmc@vger.kernel.org>,
        Baolin Wang <baolin.wang7@gmail.com>,
        Orson Zhai <orsonzhai@gmail.com>,
        Chunyan Zhang <chunyan.zhang@unisoc.com>,
        zhenxiong.lai@unisoc.com, yuelin.tang@unisoc.com,
        LKML <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Sun, 26 Sept 2021 at 11:28, Chunyan Zhang <zhang.lyra@gmail.com> wrote:
>
> From: Zhenxiong Lai <zhenxiong.lai@unisoc.com>
>
> According to the specification, DLL status has to be locked before using it.
>
> Signed-off-by: Zhenxiong Lai <zhenxiong.lai@unisoc.com>
> Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>

Applied for next, thanks!

Kind regards
Uffe


> ---
> Changes since v1:
> * Use read_poll_timeout() instead of while loop.
> ---
>  drivers/mmc/host/sdhci-sprd.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-sprd.c b/drivers/mmc/host/sdhci-sprd.c
> index 11e375579cfb..f33e9349e4e6 100644
> --- a/drivers/mmc/host/sdhci-sprd.c
> +++ b/drivers/mmc/host/sdhci-sprd.c
> @@ -8,6 +8,7 @@
>  #include <linux/delay.h>
>  #include <linux/dma-mapping.h>
>  #include <linux/highmem.h>
> +#include <linux/iopoll.h>
>  #include <linux/module.h>
>  #include <linux/of.h>
>  #include <linux/of_device.h>
> @@ -39,6 +40,9 @@
>  #define  SDHCI_SPRD_BIT_POSRD_DLY_INV          BIT(21)
>  #define  SDHCI_SPRD_BIT_NEGRD_DLY_INV          BIT(29)
>
> +#define SDHCI_SPRD_REG_32_DLL_STS0     0x210
> +#define SDHCI_SPRD_DLL_LOCKED          BIT(18)
> +
>  #define SDHCI_SPRD_REG_32_BUSY_POSI            0x250
>  #define  SDHCI_SPRD_BIT_OUTR_CLK_AUTO_EN       BIT(25)
>  #define  SDHCI_SPRD_BIT_INNR_CLK_AUTO_EN       BIT(24)
> @@ -256,6 +260,15 @@ static void sdhci_sprd_enable_phy_dll(struct sdhci_host *host)
>         sdhci_writel(host, tmp, SDHCI_SPRD_REG_32_DLL_CFG);
>         /* wait 1ms */
>         usleep_range(1000, 1250);
> +
> +       if (read_poll_timeout(sdhci_readl, tmp, (tmp & SDHCI_SPRD_DLL_LOCKED),
> +               2000, USEC_PER_SEC, false, host, SDHCI_SPRD_REG_32_DLL_STS0)) {
> +               pr_err("%s: DLL locked fail!\n", mmc_hostname(host->mmc));
> +               pr_info("%s: DLL_STS0 : 0x%x, DLL_CFG : 0x%x\n",
> +                        mmc_hostname(host->mmc),
> +                        sdhci_readl(host, SDHCI_SPRD_REG_32_DLL_STS0),
> +                        sdhci_readl(host, SDHCI_SPRD_REG_32_DLL_CFG));
> +       }
>  }
>
>  static void sdhci_sprd_set_clock(struct sdhci_host *host, unsigned int clock)
> --
> 2.25.1
>