Re: [PATCH 3.10] mmc: block: fix a bug of error handling in MMC driver

[Luis Henriques <luis.henriques@canonical.com>]

On Fri, Dec 06, 2013 at 01:45:33AM +0900, Yoshitake Kobayashi wrote:
> From: KOBAYASHI Yoshitake <yoshitake.kobayashi@toshiba.co.jp>
> 
> commit c8760069627ad3b0dbbea170f0c4c58b16e18d3d upstream.

Thank you, I'm queuing this patch to the 3.11 kernel as well.

Cheers,
--
Luis


> 
> Current MMC driver doesn't handle generic error (bit19 of device
> status) in write sequence. As a result, write data gets lost when
> generic error occurs. For example, a generic error when updating a
> filesystem management information causes a loss of write data and
> corrupts the filesystem. In the worst case, the system will never
> boot.
> 
> This patch includes the following functionality:
>   1. To enable error checking for the response of CMD12 and CMD13
>      in write command sequence
>   2. To retry write sequence when a generic error occurs
> 
> Signed-off-by: KOBAYASHI Yoshitake <yoshitake.kobayashi@toshiba.co.jp>
> Signed-off-by: Chris Ball <cjb@laptop.org>
> ---
>  drivers/mmc/card/block.c |   45 ++++++++++++++++++++++++++++++++++++++++++---
>  1 files changed, 42 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
> index dd27b07..76a3d3a 100644
> --- a/drivers/mmc/card/block.c
> +++ b/drivers/mmc/card/block.c
> @@ -769,7 +769,7 @@ static int mmc_blk_cmd_error(struct request *req, const char *name, int error,
>   * Otherwise we don't understand what happened, so abort.
>   */
>  static int mmc_blk_cmd_recovery(struct mmc_card *card, struct request *req,
> -	struct mmc_blk_request *brq, int *ecc_err)
> +	struct mmc_blk_request *brq, int *ecc_err, int *gen_err)
>  {
>  	bool prev_cmd_status_valid = true;
>  	u32 status, stop_status = 0;
> @@ -807,6 +807,16 @@ static int mmc_blk_cmd_recovery(struct mmc_card *card, struct request *req,
>  	    (brq->cmd.resp[0] & R1_CARD_ECC_FAILED))
>  		*ecc_err = 1;
>  
> +	/* Flag General errors */
> +	if (!mmc_host_is_spi(card->host) && rq_data_dir(req) != READ)
> +		if ((status & R1_ERROR) ||
> +			(brq->stop.resp[0] & R1_ERROR)) {
> +			pr_err("%s: %s: general error sending stop or status command, stop cmd response %#x, card status %#x\n",
> +			       req->rq_disk->disk_name, __func__,
> +			       brq->stop.resp[0], status);
> +			*gen_err = 1;
> +		}
> +
>  	/*
>  	 * Check the current card state.  If it is in some data transfer
>  	 * mode, tell it to stop (and hopefully transition back to TRAN.)
> @@ -826,6 +836,13 @@ static int mmc_blk_cmd_recovery(struct mmc_card *card, struct request *req,
>  			return ERR_ABORT;
>  		if (stop_status & R1_CARD_ECC_FAILED)
>  			*ecc_err = 1;
> +		if (!mmc_host_is_spi(card->host) && rq_data_dir(req) != READ)
> +			if (stop_status & R1_ERROR) {
> +				pr_err("%s: %s: general error sending stop command, stop cmd response %#x\n",
> +				       req->rq_disk->disk_name, __func__,
> +				       stop_status);
> +				*gen_err = 1;
> +			}
>  	}
>  
>  	/* Check for set block count errors */
> @@ -1069,7 +1086,7 @@ static int mmc_blk_err_check(struct mmc_card *card,
>  						    mmc_active);
>  	struct mmc_blk_request *brq = &mq_mrq->brq;
>  	struct request *req = mq_mrq->req;
> -	int ecc_err = 0;
> +	int ecc_err = 0, gen_err = 0;
>  
>  	/*
>  	 * sbc.error indicates a problem with the set block count
> @@ -1083,7 +1100,7 @@ static int mmc_blk_err_check(struct mmc_card *card,
>  	 */
>  	if (brq->sbc.error || brq->cmd.error || brq->stop.error ||
>  	    brq->data.error) {
> -		switch (mmc_blk_cmd_recovery(card, req, brq, &ecc_err)) {
> +		switch (mmc_blk_cmd_recovery(card, req, brq, &ecc_err, &gen_err)) {
>  		case ERR_RETRY:
>  			return MMC_BLK_RETRY;
>  		case ERR_ABORT:
> @@ -1115,6 +1132,14 @@ static int mmc_blk_err_check(struct mmc_card *card,
>  		u32 status;
>  		unsigned long timeout;
>  
> +		/* Check stop command response */
> +		if (brq->stop.resp[0] & R1_ERROR) {
> +			pr_err("%s: %s: general error sending stop command, stop cmd response %#x\n",
> +			       req->rq_disk->disk_name, __func__,
> +			       brq->stop.resp[0]);
> +			gen_err = 1;
> +		}
> +
>  		timeout = jiffies + msecs_to_jiffies(MMC_BLK_TIMEOUT_MS);
>  		do {
>  			int err = get_card_status(card, &status, 5);
> @@ -1124,6 +1149,13 @@ static int mmc_blk_err_check(struct mmc_card *card,
>  				return MMC_BLK_CMD_ERR;
>  			}
>  
> +			if (status & R1_ERROR) {
> +				pr_err("%s: %s: general error sending status command, card status %#x\n",
> +				       req->rq_disk->disk_name, __func__,
> +				       status);
> +				gen_err = 1;
> +			}
> +
>  			/* Timeout if the device never becomes ready for data
>  			 * and never leaves the program state.
>  			 */
> @@ -1143,6 +1175,13 @@ static int mmc_blk_err_check(struct mmc_card *card,
>  			 (R1_CURRENT_STATE(status) == R1_STATE_PRG));
>  	}
>  
> +	/* if general error occurs, retry the write operation. */
> +	if (gen_err) {
> +		pr_warn("%s: retrying write for general error\n",
> +				req->rq_disk->disk_name);
> +		return MMC_BLK_RETRY;
> +	}
> +
>  	if (brq->data.error) {
>  		pr_err("%s: error %d transferring data, sector %u, nr %u, cmd response %#x, card status %#x\n",
>  		       req->rq_disk->disk_name, brq->data.error,
> -- 
> 1.7.0.4
> 
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