linux-kernel - Re: [PATCH 1/2] mmc: sdio: Move code to get pending SDIO IRQs to a function

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Date:   Thu, 29 Aug 2019 10:29:26 +0200
From:   Ulf Hansson <ulf.hansson@...aro.org>
To:     Matthias Kaehlcke <mka@...omium.org>
Cc:     Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        "linux-mmc@...r.kernel.org" <linux-mmc@...r.kernel.org>,
        Douglas Anderson <dianders@...omium.org>
Subject: Re: [PATCH 1/2] mmc: sdio: Move code to get pending SDIO IRQs to a function

On Wed, 28 Aug 2019 at 23:46, Matthias Kaehlcke <mka@...omium.org> wrote:
>
> Move the code to get pending SDIO interrupts from
> process_sdio_pending_irqs() to a dedicated function.
>
> Signed-off-by: Matthias Kaehlcke <mka@...omium.org>
> ---
>  drivers/mmc/core/sdio_irq.c | 47 ++++++++++++++++++++++++-------------
>  include/linux/mmc/host.h    |  1 +
>  2 files changed, 32 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/mmc/core/sdio_irq.c b/drivers/mmc/core/sdio_irq.c
> index 0bcc5e83bd1a..fedc49901efd 100644
> --- a/drivers/mmc/core/sdio_irq.c
> +++ b/drivers/mmc/core/sdio_irq.c
> @@ -27,6 +27,35 @@
>  #include "core.h"
>  #include "card.h"
>
> +int sdio_get_pending_irqs(struct mmc_host *host, u8 *pending)
> +{
> +       struct mmc_card *card = host->card;
> +       int ret;
> +
> +       WARN_ON(!host->claimed);
> +
> +       ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, pending);
> +       if (ret) {
> +               pr_debug("%s: error %d reading SDIO_CCCR_INTx\n",
> +                      mmc_card_id(card), ret);
> +               return ret;
> +       }
> +
> +       if (*pending && mmc_card_broken_irq_polling(card) &&
> +           !(host->caps & MMC_CAP_SDIO_IRQ)) {
> +               unsigned char dummy;
> +
> +               /* A fake interrupt could be created when we poll SDIO_CCCR_INTx
> +                * register with a Marvell SD8797 card. A dummy CMD52 read to
> +                * function 0 register 0xff can avoid this.
> +                */
> +               mmc_io_rw_direct(card, 0, 0, 0xff, 0, &dummy);
> +       }
> +
> +       return 0;
> +}
> +EXPORT_SYMBOL_GPL(sdio_get_pending_irqs);

I don't think you need export the sympol as this should be an internal
function for the core module.

> +
>  static int process_sdio_pending_irqs(struct mmc_host *host)
>  {
>         struct mmc_card *card = host->card;
> @@ -49,23 +78,9 @@ static int process_sdio_pending_irqs(struct mmc_host *host)
>                 return 1;
>         }
>
> -       ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending);
> -       if (ret) {
> -               pr_debug("%s: error %d reading SDIO_CCCR_INTx\n",
> -                      mmc_card_id(card), ret);
> +       ret = sdio_get_pending_irqs(host, &pending);
> +       if (ret)
>                 return ret;
> -       }
> -
> -       if (pending && mmc_card_broken_irq_polling(card) &&
> -           !(host->caps & MMC_CAP_SDIO_IRQ)) {
> -               unsigned char dummy;
> -
> -               /* A fake interrupt could be created when we poll SDIO_CCCR_INTx
> -                * register with a Marvell SD8797 card. A dummy CMD52 read to
> -                * function 0 register 0xff can avoid this.
> -                */
> -               mmc_io_rw_direct(card, 0, 0, 0xff, 0, &dummy);
> -       }
>
>         count = 0;
>         for (i = 1; i <= 7; i++) {
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index 4a351cb7f20f..7ce0e98e3dbd 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -502,6 +502,7 @@ static inline void mmc_signal_sdio_irq(struct mmc_host *host)
>  }
>
>  void sdio_signal_irq(struct mmc_host *host);
> +int sdio_get_pending_irqs(struct mmc_host *host, u8 *pending);

I want to avoid to sprinkle the public mmc headers, avoiding
interfaces to be abused outside mmc core.

That said, I think this should be internal to the mmc core, thus
please move this to drivers/mmc/core/sdio_ops.h.

>
>  #ifdef CONFIG_REGULATOR
>  int mmc_regulator_set_ocr(struct mmc_host *mmc,
> --
> 2.23.0.187.g17f5b7556c-goog
>

Kind regards
Uffe