[PATCH v2] mmc: sdio: Fix sdio wait busy implement limitation

[Ulf Hansson]

On 23 April 2017 at 11:38, Jiajie Hao <jiajie.hao at mediatek.com> wrote:
> The host may issue an I/O abort by writing to the CCCR at any time
> during I/O read operation via CMD52. And host may need suspend
> transcation during write busy stage in SDIO suspend/resume scenario.
> From other side, a card may accept CMD52 during data transfer phase.
>
> Previous implement would block issuing above command in busy stage.
> It cause function driver can't implement as proper way and has no
> opportunity to do some coverage in error case via I/O abort etc.
>
> We need bypass some necessary operation during busy check stage.
>
> Signed-off-by: Jiajie Hao <jiajie.hao at mediatek.com>

Thanks, applied for next!

Kind regards
Uffe

> ---
> Changes since v1:(https://lkml.org/lkml/2017/4/17/69)
>     * extend orignal interface to cover necessary cases.
>     * rename mmc_is_io_op() to sdio_is_op_busy() for matching it's meaning.
>
> ---
>  drivers/mmc/core/core.c     |    4 +++-
>  drivers/mmc/core/sdio_ops.h |   10 ++++++++--
>  2 files changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index 926e0fd..2ae83a7 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -234,8 +234,10 @@ static void __mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
>         /*
>          * For sdio rw commands we must wait for card busy otherwise some
>          * sdio devices won't work properly.
> +        * And bypass I/O abort, reset and bus suspend operations.
>          */
> -       if (mmc_is_io_op(mrq->cmd->opcode) && host->ops->card_busy) {
> +       if (sdio_is_io_busy(mrq->cmd->opcode, mrq->cmd->arg) &&
> +           host->ops->card_busy) {
>                 int tries = 500; /* Wait aprox 500ms at maximum */
>
>                 while (host->ops->card_busy(host) && --tries)
> diff --git a/drivers/mmc/core/sdio_ops.h b/drivers/mmc/core/sdio_ops.h
> index bed8a83..ee35cb4 100644
> --- a/drivers/mmc/core/sdio_ops.h
> +++ b/drivers/mmc/core/sdio_ops.h
> @@ -26,9 +26,15 @@ int mmc_io_rw_extended(struct mmc_card *card, int write, unsigned fn,
>  int sdio_reset(struct mmc_host *host);
>  unsigned int mmc_align_data_size(struct mmc_card *card, unsigned int sz);
>
> -static inline bool mmc_is_io_op(u32 opcode)
> +static inline bool sdio_is_io_busy(u32 opcode, u32 arg)
>  {
> -       return opcode == SD_IO_RW_DIRECT || opcode == SD_IO_RW_EXTENDED;
> +       u32 addr;
> +
> +       addr = (arg >> 9) & 0x1FFFF;
> +
> +       return (opcode == SD_IO_RW_EXTENDED ||
> +               (opcode == SD_IO_RW_DIRECT &&
> +               !(addr == SDIO_CCCR_ABORT || addr == SDIO_CCCR_SUSPEND)));
>  }
>
>  #endif
> --
> 1.7.9.5
>