Re: [PATCH 3.4] mmc: block: fix a bug of error handling in MMCdriver

From: Ben Hutchings
Date: Sat Dec 28 2013 - 17:55:04 EST


On Fri, 2013-12-06 at 01:47 +0900, Yoshitake Kobayashi wrote:
> From: KOBAYASHI Yoshitake <yoshitake.kobayashi@xxxxxxxxxxxxx>
>
> commit c8760069627ad3b0dbbea170f0c4c58b16e18d3d upstream.
>
> 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
>
> [Backported to 3.4-stable]
>
> Signed-off-by: KOBAYASHI Yoshitake <yoshitake.kobayashi@xxxxxxxxxxxxx>
> Signed-off-by: Chris Ball <cjb@xxxxxxxxxx>

I've also queued this up for 3.2, thanks.

Ben.

> ---
> drivers/mmc/card/block.c | 47 +++++++++++++++++++++++++++++++++++++++++++--
> 1 files changed, 44 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
> index 833ff16..91042a2 100644
> --- a/drivers/mmc/card/block.c
> +++ b/drivers/mmc/card/block.c
> @@ -701,7 +701,7 @@ 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;
> @@ -739,6 +739,16 @@ 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.)
> @@ -758,6 +768,13 @@ 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 */
> @@ -1007,7 +1024,7 @@ 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
> @@ -1021,7 +1038,7 @@ 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:
> @@ -1051,6 +1068,15 @@ static int mmc_blk_err_check(struct mmc_card *card,
> */
> if (!mmc_host_is_spi(card->host) && rq_data_dir(req) != READ) {
> u32 status;
> +
> + /* 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;
> + }
> +
> do {
> int err = get_card_status(card, &status, 5);
> if (err) {
> @@ -1058,6 +1084,14 @@ static int mmc_blk_err_check(struct mmc_card *card,
> req->rq_disk->disk_name, err);
> 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;
> + }
> +
> /*
> * Some cards mishandle the status bits,
> * so make sure to check both the busy
> @@ -1067,6 +1101,13 @@ 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_warning("%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,

--
Ben Hutchings
Kids! Bringing about Armageddon can be dangerous. Do not attempt it in
your own home. - Terry Pratchett and Neil Gaiman, `Good Omens'

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