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In-Reply-To: <b6c0c003d887bf7c272c493212f4f89d28097ad4.1583307441.git.baolin.wang7@gmail.com>
From:   Ulf Hansson <ulf.hansson@linaro.org>
Date:   Mon, 16 Mar 2020 12:47:20 +0100
Message-ID: <CAPDyKFoKzBPNFkG=4OenZ_7ZVgqfhhEDRxsSbu6cJOSgCPPL1Q@mail.gmail.com>
Subject: Re: [RESEND PATCH 2/3] mmc: host: sdhci-sprd: Implement the
 request_atomic() API
To:     Baolin Wang <baolin.wang7@gmail.com>
Cc:     Adrian Hunter <adrian.hunter@intel.com>,
        Orson Zhai <orsonzhai@gmail.com>,
        Chunyan Zhang <zhang.lyra@gmail.com>,
        Arnd Bergmann <arnd@arndb.de>,
        "linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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Sender: linux-kernel-owner@vger.kernel.org
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On Wed, 4 Mar 2020 at 08:42, Baolin Wang <baolin.wang7@gmail.com> wrote:
>
> Implement the request_atomic() API for nonremovable cards, that means
> we can submit next request in the irq hard handler context to reduce
> latency.
>
> Signed-off-by: Baolin Wang <baolin.wang7@gmail.com>
> ---
>  drivers/mmc/host/sdhci-sprd.c | 28 ++++++++++++++++++++++++++--
>  1 file changed, 26 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-sprd.c b/drivers/mmc/host/sdhci-sprd.c
> index 2ab42c5..bddf0f3 100644
> --- a/drivers/mmc/host/sdhci-sprd.c
> +++ b/drivers/mmc/host/sdhci-sprd.c
> @@ -426,6 +426,27 @@ static void sdhci_sprd_request(struct mmc_host *mmc, struct mmc_request *mrq)
>         sdhci_request(mmc, mrq);
>  }
>
> +static void sdhci_sprd_request_atomic(struct mmc_host *mmc,
> +                                     struct mmc_request *mrq)
> +{
> +       struct sdhci_host *host = mmc_priv(mmc);
> +       struct sdhci_sprd_host *sprd_host = TO_SPRD_HOST(host);
> +
> +       host->flags |= sprd_host->flags & SDHCI_AUTO_CMD23;
> +
> +       /*
> +        * From version 4.10 onward, ARGUMENT2 register is also as 32-bit
> +        * block count register which doesn't support stuff bits of
> +        * CMD23 argument on Spreadtrum's sd host controller.
> +        */
> +       if (host->version >= SDHCI_SPEC_410 &&
> +           mrq->sbc && (mrq->sbc->arg & SDHCI_SPRD_ARG2_STUFF) &&
> +           (host->flags & SDHCI_AUTO_CMD23))
> +               host->flags &= ~SDHCI_AUTO_CMD23;

Looks like the above code is a copy of what is done in
sdhci_sprd_request(). Perhaps add a helper function that deals with
this to avoid open coding?

> +
> +       sdhci_request_atomic(mmc, mrq);
> +}
> +
>  static int sdhci_sprd_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
>  {
>         struct sdhci_host *host = mmc_priv(mmc);
> @@ -561,6 +582,11 @@ static int sdhci_sprd_probe(struct platform_device *pdev)
>         if (ret)
>                 goto pltfm_free;
>
> +       if (!mmc_card_is_removable(host->mmc))
> +               host->mmc_host_ops.request_atomic = sdhci_sprd_request_atomic;
> +       else
> +               host->always_defer_done = true;
> +
>         sprd_host = TO_SPRD_HOST(host);
>         sdhci_sprd_phy_param_parse(sprd_host, pdev->dev.of_node);
>
> @@ -654,8 +680,6 @@ static int sdhci_sprd_probe(struct platform_device *pdev)
>         if (ret)
>                 goto err_cleanup_host;
>
> -       host->always_defer_done = true;
> -
>         ret = __sdhci_add_host(host);
>         if (ret)
>                 goto err_cleanup_host;
> --
> 1.9.1
>

Kind regards
Uffe