[PATCH 3.4 26/32] mmc: block: fix a bug of error handling in MMC driver

Greg Kroah-Hartman
2013-12-06T21:56:42Z

From: KOBAYASHI Yoshitake <yoshitake.kobayashi@toshiba.co.jp>

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

Messages are added for v2 to show what occurs.

Signed-off-by: KOBAYASHI Yoshitake <yoshitake.kobayashi@toshiba.co.jp>
Signed-off-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/mmc/card/block.c | 47 ++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 44 insertions(+), 3 deletions(-)

--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -701,7 +701,7 @@ static int mmc_blk_cmd_error(struct requ
* 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 m
(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 m
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_
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_
*/
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_
*/
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_
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_
(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,