Re: [PATCH 1/2] mmc: core: Prevent I/O as soon as possible at card removal

[Adrian Hunter <adrian.hunter@intel.com>]

On 19/01/12 18:39, Ulf Hansson wrote:
> Once the card has been detected to be removed by the
> mmc_detect_card_removed function, schedule a new detect work
> immediately and without a delay to let a rescan remove the
> card device as soon a possible. This will sooner prevent
> further I/O requests.
> 
> Signed-off-by: Ulf Hansson <ulf.hansson@stericsson.com>
> ---
>  drivers/mmc/core/core.c |   16 ++++++++++++++--
>  1 files changed, 14 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index bec0bf2..265dfd8 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -2077,6 +2077,7 @@ int _mmc_detect_card_removed(struct mmc_host *host)
>  int mmc_detect_card_removed(struct mmc_host *host)
>  {
>  	struct mmc_card *card = host->card;
> +	int ret;
>  
>  	WARN_ON(!host->claimed);
>  	/*
> @@ -2086,9 +2087,20 @@ int mmc_detect_card_removed(struct mmc_host *host)
>  	if (card && !host->detect_change && !(host->caps & MMC_CAP_NEEDS_POLL))
>  		return mmc_card_removed(card);
>  
> -	host->detect_change = 0;

That line should not be removed.  It is not related to your change.

> +	ret = mmc_card_removed(card);

Calling mmc_card_removed() is not needed here since
_mmc_detect_card_removed() does it anyway.

> +	if (!ret) {
> +		ret = _mmc_detect_card_removed(host);
> +		if (ret) {
> +			/*
> +			 * Schedule a detect work as soon as possible to let a
> +			 * rescan handle the card removal.
> +			 */
> +			cancel_delayed_work(&host->detect);

Why cancel the detect work?

> +			mmc_detect_change(host, 0);
> +		}
> +	}
>  
> -	return _mmc_detect_card_removed(host);
> +	return ret;
>  }
>  EXPORT_SYMBOL(mmc_detect_card_removed);
>