Re: [PATCH V2] mmc: core: Clean up after mmc_pre_req if card was removed

[Ulf Hansson <ulf.hansson@stericsson.com>]

Hi Jaehoon,

I would be very interested to hear if you still encounter any problems 
with this V2 patch? If you are able to do a test it would be highly 
appreciated. :-)

Just for reference, I were able to reproduce problems similar to what 
you have for the V1 patch.

Thanks!

Best regards
Ulf Hansson


On 03/05/2012 03:52 PM, Ulf HANSSON wrote:
> Make sure mmc_start_req cancel the prepared job, if the request
> was prevented to be started due to the card has been removed.
>
> This bug was introduced in commit:
> mmc: allow upper layers to know immediately if card has been removed
>
> Signed-off-by: Ulf Hansson<ulf.hansson@stericsson.com>
> Reviewed-by: Per Forlin<per.forlin@stericsson.com>
> ---
>
> Changes in v2:
> 	- Maintain handling of host->areq (host->areq must not be NULL when
> 	"start_err"), to make sure the block layer is able to respond to all
> 	of the started requests.
>
> ---
>   drivers/mmc/core/core.c |   35 +++++++++++++++--------------------
>   1 files changed, 15 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index faa0af1..56b7a24 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -249,16 +249,17 @@ static void mmc_wait_done(struct mmc_request *mrq)
>   	complete(&mrq->completion);
>   }
>
> -static void __mmc_start_req(struct mmc_host *host, struct mmc_request *mrq)
> +static int __mmc_start_req(struct mmc_host *host, struct mmc_request *mrq)
>   {
>   	init_completion(&mrq->completion);
>   	mrq->done = mmc_wait_done;
>   	if (mmc_card_removed(host->card)) {
>   		mrq->cmd->error = -ENOMEDIUM;
>   		complete(&mrq->completion);
> -		return;
> +		return -ENOMEDIUM;
>   	}
>   	mmc_start_request(host, mrq);
> +	return 0;
>   }
>
>   static void mmc_wait_for_req_done(struct mmc_host *host,
> @@ -342,6 +343,7 @@ struct mmc_async_req *mmc_start_req(struct mmc_host *host,
>   				    struct mmc_async_req *areq, int *error)
>   {
>   	int err = 0;
> +	int start_err = 0;
>   	struct mmc_async_req *data = host->areq;
>
>   	/* Prepare a new request */
> @@ -351,30 +353,23 @@ struct mmc_async_req *mmc_start_req(struct mmc_host *host,
>   	if (host->areq) {
>   		mmc_wait_for_req_done(host, host->areq->mrq);
>   		err = host->areq->err_check(host->card, host->areq);
> -		if (err) {
> -			/* post process the completed failed request */
> -			mmc_post_req(host, host->areq->mrq, 0);
> -			if (areq)
> -				/*
> -				 * Cancel the new prepared request, because
> -				 * it can't run until the failed
> -				 * request has been properly handled.
> -				 */
> -				mmc_post_req(host, areq->mrq, -EINVAL);
> -
> -			host->areq = NULL;
> -			goto out;
> -		}
>   	}
>
> -	if (areq)
> -		__mmc_start_req(host, areq->mrq);
> +	if (!err&&  areq)
> +		start_err = __mmc_start_req(host, areq->mrq);
>
>   	if (host->areq)
>   		mmc_post_req(host, host->areq->mrq, 0);
>
> -	host->areq = areq;
> - out:
> +	 /* Cancel a prepared request if it was not started. */
> +	if ((err || start_err)&&  areq)
> +			mmc_post_req(host, areq->mrq, -EINVAL);
> +
> +	if (err)
> +		host->areq = NULL;
> +	else
> +		host->areq = areq;
> +
>   	if (error)
>   		*error = err;
>   	return data;