Re: [PATCH] MMC: Refine block layer waiting for card state

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

On 27/09/10 06:32, Ethan Du wrote:
>
>      The while loop when handling rw request may become deadloop in
> case of bad card
>      I've seen mmcqd gets blocked forever after a single error message:
>
> mmcblk0: error -110 sending read/write command, response 0x900, card
> status 0x80e00
>
>      Also there was case of card reports status without error
>
> mmcblk0: error -110 sending read/write command, response 0x900, card
> status 0xe00
>
>      After this error, the card can stay in prg state, and never comes back,
>      and may not report any error further. So a break out condition
>      should be set in mmc block layer:
> * should not enter the waiting loop in case of error

How do you know there are not any errors where you do need to wait?

> * should break out from the waiting loop, if card response with error
> * should break out from the waiting loop when timeout
>
>      These will not help with the card, one more thing to do:
> * re-init the card in case of too many errors

Using mmc_detect_change() will give you a new block device.
That is probably a bad idea for a non-removable card.  Also
if the reinitialization is going to help, then why wait for
lots of errors before doing it.

>
> Signed-off-by: Ethan Du<ethan.too@gmail.com>
> ---
>   drivers/mmc/card/block.c |   35 +++++++++++++++++++++++++++--------
>   drivers/mmc/core/mmc.c   |    9 +++++++--
>   drivers/mmc/core/sd.c    |    8 ++++++--
>   include/linux/mmc/card.h |    3 +++
>   include/linux/mmc/mmc.h  |    1 +
>   5 files changed, 44 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
> index d545f79..1d304a2 100644
> --- a/drivers/mmc/card/block.c
> +++ b/drivers/mmc/card/block.c
> @@ -316,12 +316,14 @@ out:
>   	return err ? 0 : 1;
>   }
>
> +#define BUSY_TIMEOUT_MS (16 * 1024)
>   static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)
>   {
>   	struct mmc_blk_data *md = mq->data;
>   	struct mmc_card *card = md->queue.card;
>   	struct mmc_blk_request brq;
>   	int ret = 1, disable_multi = 0;
> +	unsigned long timeout = 0;
>
>   	mmc_claim_host(card->host);
>
> @@ -453,7 +455,9 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue
> *mq, struct request *req)
>   			       brq.stop.resp[0], status);
>   		}
>
> -		if (!mmc_host_is_spi(card->host)&&  rq_data_dir(req) != READ) {
> +		if (!mmc_host_is_spi(card->host)&&  rq_data_dir(req) != READ&&
> +		    !brq.cmd.error&&  !brq.data.error&&  !brq.stop.error) {
> +			timeout = jiffies + msecs_to_jiffies(BUSY_TIMEOUT_MS);
>   			do {
>   				int err;
>
> @@ -466,13 +470,22 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue
> *mq, struct request *req)
>   					       req->rq_disk->disk_name, err);
>   					goto cmd_err;
>   				}
> +				if (cmd.resp[0]&  R1_ERROR_MASK) {
> +					printk(KERN_ERR "%s: card err %#x\n",
> +						req->rq_disk->disk_name,
> +						cmd.resp[0]);
> +					goto cmd_err;
> +				}
>   				/*
>   				 * Some cards mishandle the status bits,
>   				 * so make sure to check both the busy
>   				 * indication and the card state.
>   				 */
> -			} while (!(cmd.resp[0]&  R1_READY_FOR_DATA) ||
> -				(R1_CURRENT_STATE(cmd.resp[0]) == 7));
> +				if ((cmd.resp[0]&  R1_READY_FOR_DATA)&&
> +				    (R1_CURRENT_STATE(cmd.resp[0]) != 7))
> +					break;
> +			} while (time_before(jiffies, timeout));
> +			/* Ignore timeout out */
>
>   #if 0
>   			if (cmd.resp[0]&  ~0x00000900)
> @@ -510,11 +523,11 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue
> *mq, struct request *req)
>
>   	return 1;
>
> - cmd_err:
> - 	/*
> - 	 * If this is an SD card and we're writing, we can first
> - 	 * mark the known good sectors as ok.
> - 	 *
> +cmd_err:
> +	/*
> +	 * If this is an SD card and we're writing, we can first
> +	 * mark the known good sectors as ok.
> +	 *
>   	 * If the card is not SD, we can still ok written sectors
>   	 * as reported by the controller (which might be less than
>   	 * the real number of written sectors, but never more).
> @@ -541,6 +554,12 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue
> *mq, struct request *req)
>   		ret = __blk_end_request(req, -EIO, blk_rq_cur_bytes(req));
>   	spin_unlock_irq(&md->lock);
>
> +	card->err_count++;
> +	if (card->err_count>= ERR_TRIGGER_REINIT) {
> +		printk(KERN_WARNING "%s: re-init the card due to error\n",
> +			req->rq_disk->disk_name);
> +		mmc_detect_change(card->host, 0);
> +	}
>   	return 0;
>   }
>
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index 6909a54..79c4759 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -535,6 +535,8 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
>
>   	if (!oldcard)
>   		host->card = card;
> +	else
> +		oldcard->err_count = 0;
>
>   	return 0;
>
> @@ -563,17 +565,20 @@ static void mmc_remove(struct mmc_host *host)
>    */
>   static void mmc_detect(struct mmc_host *host)
>   {
> -	int err;
> +	int err = 0;
>
>   	BUG_ON(!host);
>   	BUG_ON(!host->card);
>
>   	mmc_claim_host(host);
>
> +	if (host->card->err_count>= ERR_TRIGGER_REINIT)
> +		err = mmc_init_card(host, host->ocr, host->card);
>   	/*
>   	 * Just check if our card has been removed.
>   	 */
> -	err = mmc_send_status(host->card, NULL);
> +	if (!err)
> +		err = mmc_send_status(host->card, NULL);
>
>   	mmc_release_host(host);
>
> diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
> index 0f52410..820b0d1 100644
> --- a/drivers/mmc/core/sd.c
> +++ b/drivers/mmc/core/sd.c
> @@ -635,6 +635,7 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
>   		mmc_set_bus_width(host, MMC_BUS_WIDTH_4);
>   	}
>
> +	card->err_count = 0;
>   	host->card = card;
>   	return 0;
>
> @@ -662,17 +663,20 @@ static void mmc_sd_remove(struct mmc_host *host)
>    */
>   static void mmc_sd_detect(struct mmc_host *host)
>   {
> -	int err;
> +	int err = 0;
>
>   	BUG_ON(!host);
>   	BUG_ON(!host->card);
>
>   	mmc_claim_host(host);
>
> +	if (host->card->err_count>= ERR_TRIGGER_REINIT)
> +		err = mmc_sd_init_card(host, host->ocr, host->card);
>   	/*
>   	 * Just check if our card has been removed.
>   	 */
> -	err = mmc_send_status(host->card, NULL);
> +	if (!err)
> +		err = mmc_send_status(host->card, NULL);
>
>   	mmc_release_host(host);
>
> diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
> index 6b75250..178de17 100644
> --- a/include/linux/mmc/card.h
> +++ b/include/linux/mmc/card.h
> @@ -143,6 +143,9 @@ struct mmc_card {
>   	const char		**info;		/* info strings */
>   	struct sdio_func_tuple	*tuples;	/* unknown common tuples */
>
> +	unsigned int		err_count;
> +#define ERR_TRIGGER_REINIT 1024
> +
>   	struct dentry		*debugfs_root;
>   };
>
> diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
> index dd11ae5..3b979a1 100644
> --- a/include/linux/mmc/mmc.h
> +++ b/include/linux/mmc/mmc.h
> @@ -122,6 +122,7 @@
>   #define R1_UNDERRUN		(1<<  18)	/* ex, c */
>   #define R1_OVERRUN		(1<<  17)	/* ex, c */
>   #define R1_CID_CSD_OVERWRITE	(1<<  16)	/* erx, c, CID/CSD overwrite */
> +#define R1_ERROR_MASK		0xffff0000
>   #define R1_WP_ERASE_SKIP	(1<<  15)	/* sx, c */
>   #define R1_CARD_ECC_DISABLED	(1<<  14)	/* sx, a */
>   #define R1_ERASE_RESET		(1<<  13)	/* sr, c */