Re: [PATCH 1/1] MMC: core/core.c: mmc_rescan detects card changein one run

[Jörg Schummer]

On Fri, 2009-04-10 at 18:39 +0200, ext Pierre Ossman wrote:
> On Tue, 31 Mar 2009 17:51:21 +0300
> Jorg Schummer <ext-jorg.2.schummer@xxxxxxxxx> wrote:
> 
> > With this patch, mmc_rescan can detect the removal of an mmc card and
> > the insertion of (possibly another) card in the same run. This means
> > that a card change can be detected without having to call
> > mmc_detect_change multiple times.
> > 
> > This change generalises the core such that it can be easily used by
> > hosts which provide a mechanism to detect only the presence of a card
> > reader cover, which has to be taken off in order to insert a card. Other
> > hosts ("card detect" or "MMC_CAP_NEEDS_POLL") each receive an event when
> > a card is removed and when a card is inserted, so it is sufficient for
> > them if mmc_rescan handles only one event at a time. "Cover detect"
> > hosts, however, only receive events about the cover status. This means
> > that between 2 subsequent events, both a card removal and a card
> > insertion can occur. In this case, the pre-patch version of mmc_rescan
> > would only detect the removal of the previous card but not the insertion
> > of the new card.
> > 
> > Signed-off-by: Jorg Schummer <ext-jorg.2.schummer@xxxxxxxxx>
> > ---
> 
> Queued, thanks.

Hi Pierre,

is there any news about this patch?

Regards,
JÃrg

> --- Begin Message ---
> With this patch, mmc_rescan can detect the removal of an mmc card and
> the insertion of (possibly another) card in the same run. This means
> that a card change can be detected without having to call
> mmc_detect_change multiple times.
>
> This change generalises the core such that it can be easily used by
> hosts which provide a mechanism to detect only the presence of a card
> reader cover, which has to be taken off in order to insert a card. Other
> hosts ("card detect" or "MMC_CAP_NEEDS_POLL") each receive an event when
> a card is removed and when a card is inserted, so it is sufficient for
> them if mmc_rescan handles only one event at a time. "Cover detect"
> hosts, however, only receive events about the cover status. This means
> that between 2 subsequent events, both a card removal and a card
> insertion can occur. In this case, the pre-patch version of mmc_rescan
> would only detect the removal of the previous card but not the insertion
> of the new card.
>
> Signed-off-by: Jorg Schummer <ext-jorg.2.schummer@xxxxxxxxx>
> ---
>  drivers/mmc/core/core.c |   99 ++++++++++++++++++++++++++---------------------
>  1 files changed, 55 insertions(+), 44 deletions(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index df6ce4a..5970719 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -740,61 +740,72 @@ void mmc_rescan(struct work_struct *work)
>  
>  	mmc_bus_get(host);
>  
> -	if (host->bus_ops == NULL) {
> -		/*
> -		 * Only we can add a new handler, so it's safe to
> -		 * release the lock here.
> -		 */
> +	/* if there is a card registered, check whether it is still present */
> +	if ((host->bus_ops != NULL) && host->bus_ops->detect && !host->bus_dead)
> +		host->bus_ops->detect(host);
> +
> +	mmc_bus_put(host);
> +
> +
> +	mmc_bus_get(host);
> +
> +	/* if there still is a card present, stop here */
> +	if (host->bus_ops != NULL) {
>  		mmc_bus_put(host);
> +		goto out;
> +	}
>  
> -		if (host->ops->get_cd && host->ops->get_cd(host) == 0)
> -			goto out;
> +	/* detect a newly inserted card */
>  
> -		mmc_claim_host(host);
> +	/*
> +	 * Only we can add a new handler, so it's safe to
> +	 * release the lock here.
> +	 */
> +	mmc_bus_put(host);
>  
> -		mmc_power_up(host);
> -		mmc_go_idle(host);
> +	if (host->ops->get_cd && host->ops->get_cd(host) == 0)
> +		goto out;
>  
> -		mmc_send_if_cond(host, host->ocr_avail);
> +	mmc_claim_host(host);
>  
> -		/*
> -		 * First we search for SDIO...
> -		 */
> -		err = mmc_send_io_op_cond(host, 0, &ocr);
> -		if (!err) {
> -			if (mmc_attach_sdio(host, ocr))
> -				mmc_power_off(host);
> -			goto out;
> -		}
> +	mmc_power_up(host);
> +	mmc_go_idle(host);
>  
> -		/*
> -		 * ...then normal SD...
> -		 */
> -		err = mmc_send_app_op_cond(host, 0, &ocr);
> -		if (!err) {
> -			if (mmc_attach_sd(host, ocr))
> -				mmc_power_off(host);
> -			goto out;
> -		}
> +	mmc_send_if_cond(host, host->ocr_avail);
>  
> -		/*
> -		 * ...and finally MMC.
> -		 */
> -		err = mmc_send_op_cond(host, 0, &ocr);
> -		if (!err) {
> -			if (mmc_attach_mmc(host, ocr))
> -				mmc_power_off(host);
> -			goto out;
> -		}
> +	/*
> +	 * First we search for SDIO...
> +	 */
> +	err = mmc_send_io_op_cond(host, 0, &ocr);
> +	if (!err) {
> +		if (mmc_attach_sdio(host, ocr))
> +			mmc_power_off(host);
> +		goto out;
> +	}
>  
> -		mmc_release_host(host);
> -		mmc_power_off(host);
> -	} else {
> -		if (host->bus_ops->detect && !host->bus_dead)
> -			host->bus_ops->detect(host);
> +	/*
> +	 * ...then normal SD...
> +	 */
> +	err = mmc_send_app_op_cond(host, 0, &ocr);
> +	if (!err) {
> +		if (mmc_attach_sd(host, ocr))
> +			mmc_power_off(host);
> +		goto out;
> +	}
>  
> -		mmc_bus_put(host);
> +	/*
> +	 * ...and finally MMC.
> +	 */
> +	err = mmc_send_op_cond(host, 0, &ocr);
> +	if (!err) {
> +		if (mmc_attach_mmc(host, ocr))
> +			mmc_power_off(host);
> +		goto out;
>  	}
> +
> +	mmc_release_host(host);
> +	mmc_power_off(host);
> +
>  out:
>  	if (host->caps & MMC_CAP_NEEDS_POLL)
>  		mmc_schedule_delayed_work(&host->detect, HZ);
> -- 
> 1.5.4.3
>
>
> --- End Message ---