[PATCH V14 20/24] mmc: block: blk-mq: Stop using legacy recovery

Adrian Hunter
2017-11-21T13:42:46Z

There are only a few things the recovery needs to do. Primarily, it just
needs to:
Determine the number of bytes transferred
Get the card back to transfer state
Determine whether to retry

There are also a couple of additional features:
Reset the card before the last retry
Read one sector at a time

The legacy code spent much effort analyzing command errors, but commands
fail fast, so it is simpler just to give all command errors the same number
of retries.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
drivers/mmc/core/block.c | 289 +++++++++++++++++++++++++----------------------
1 file changed, 153 insertions(+), 136 deletions(-)

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index ac976c84571f..af445e405488 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -1549,9 +1549,11 @@ static void mmc_blk_eval_resp_error(struct mmc_blk_request *brq)
}
}

-static enum mmc_blk_status __mmc_blk_err_check(struct mmc_card *card,
- struct mmc_queue_req *mq_mrq)
+static enum mmc_blk_status mmc_blk_err_check(struct mmc_card *card,
+ struct mmc_async_req *areq)
{
+ struct mmc_queue_req *mq_mrq = container_of(areq, struct mmc_queue_req,
+ areq);
struct mmc_blk_request *brq = &mq_mrq->brq;
struct request *req = mmc_queue_req_to_req(mq_mrq);
int need_retune = card->host->need_retune;
@@ -1656,15 +1658,6 @@ static enum mmc_blk_status __mmc_blk_err_check(struct mmc_card *card,
return MMC_BLK_SUCCESS;
}

-static enum mmc_blk_status mmc_blk_err_check(struct mmc_card *card,
- struct mmc_async_req *areq)
-{
- struct mmc_queue_req *mq_mrq = container_of(areq, struct mmc_queue_req,
- areq);
-
- return __mmc_blk_err_check(card, mq_mrq);
-}
-
static void mmc_blk_data_prep(struct mmc_queue *mq, struct mmc_queue_req *mqrq,
int disable_multi, bool *do_rel_wr_p,
bool *do_data_tag_p)
@@ -1990,6 +1983,7 @@ static void mmc_blk_rw_rq_prep(struct mmc_queue_req *mqrq,
}

#define MMC_MAX_RETRIES 5
+#define MMC_DATA_RETRIES 2
#define MMC_NO_RETRIES (MMC_MAX_RETRIES + 1)

/* Single sector read during recovery */
@@ -2022,6 +2016,85 @@ static void mmc_blk_ss_read(struct mmc_queue *mq, struct request *req)
mqrq->retries = MMC_NO_RETRIES;
}

+static inline bool mmc_blk_oor_valid(struct mmc_blk_request *brq)
+{
+ return !!brq->mrq.sbc;
+}
+
+static inline u32 mmc_blk_stop_err_bits(struct mmc_blk_request *brq)
+{
+ return mmc_blk_oor_valid(brq) ? CMD_ERRORS : CMD_ERRORS_EXCL_OOR;
+}
+
+/*
+ * Check for errors the host controller driver might not have seen such as
+ * response mode errors or invalid card state.
+ */
+static bool mmc_blk_status_error(struct request *req, u32 status)
+{
+ struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
+ struct mmc_blk_request *brq = &mqrq->brq;
+ struct mmc_queue *mq = req->q->queuedata;
+ u32 stop_err_bits;
+
+ if (mmc_host_is_spi(mq->card->host))
+ return 0;
+
+ stop_err_bits = mmc_blk_stop_err_bits(brq);
+
+ return brq->cmd.resp[0] & CMD_ERRORS ||
+ brq->stop.resp[0] & stop_err_bits ||
+ status & stop_err_bits ||
+ (rq_data_dir(req) == WRITE && !mmc_blk_in_tran_state(status));
+}
+
+static inline bool mmc_blk_cmd_started(struct mmc_blk_request *brq)
+{
+ return !brq->sbc.error && !brq->cmd.error &&
+ !(brq->cmd.resp[0] & CMD_ERRORS);
+}
+
+static int mmc_blk_send_stop(struct mmc_card *card)
+{
+ struct mmc_command cmd = {
+ .opcode = MMC_STOP_TRANSMISSION,
+ .flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC,
+ };
+
+ return mmc_wait_for_cmd(card->host, &cmd, 5);
+}
+
+static int mmc_blk_fix_state(struct mmc_card *card, struct request *req)
+{
+ int err;
+
+ mmc_retune_hold_now(card->host);
+
+ mmc_blk_send_stop(card);
+
+ err = card_busy_detect(card, false, req, NULL);
+
+ mmc_retune_release(card->host);
+
+ return err;
+}
+
+/*
+ * Requests are completed by mmc_blk_mq_complete_rq() which sets simple
+ * policy:
+ * 1. A request that has transferred at least some data is considered
+ * successful and will be requeued if there is remaining data to
+ * transfer.
+ * 2. Otherwise the number of retries is incremented and the request
+ * will be requeued if there are remaining retries.
+ * 3. Otherwise the request will be errored out.
+ * That means mmc_blk_mq_complete_rq() is controlled by bytes_xfered and
+ * mqrq->retries. So there are only 4 possible actions here:
+ * 1. do not accept the bytes_xfered value i.e. set it to zero
+ * 2. change mqrq->retries to determine the number of retries
+ * 3. try to reset the card
+ * 4. read one sector at a time
+ */
static void mmc_blk_mq_rw_recovery(struct mmc_queue *mq, struct request *req)
{
int type = rq_data_dir(req) == READ ? MMC_BLK_READ : MMC_BLK_WRITE;
@@ -2029,131 +2102,85 @@ static void mmc_blk_mq_rw_recovery(struct mmc_queue *mq, struct request *req)
struct mmc_blk_request *brq = &mqrq->brq;
struct mmc_blk_data *md = mq->blkdata;
struct mmc_card *card = mq->card;
- static enum mmc_blk_status status;
-
- brq->retune_retry_done = mqrq->retries;
+ u32 status;
+ u32 blocks;
+ int err;

- status = __mmc_blk_err_check(card, mqrq);
+ /*
+ * Some errors the host driver might not have seen. Set the number of
+ * bytes transferred to zero in that case.
+ */
+ err = __mmc_send_status(card, &status, 0);
+ if (err || mmc_blk_status_error(req, status))
+ brq->data.bytes_xfered = 0;

mmc_retune_release(card->host);

/*
- * Requests are completed by mmc_blk_mq_complete_rq() which sets simple
- * policy:
- * 1. A request that has transferred at least some data is considered
- * successful and will be requeued if there is remaining data to
- * transfer.
- * 2. Otherwise the number of retries is incremented and the request
- * will be requeued if there are remaining retries.
- * 3. Otherwise the request will be errored out.
- * That means mmc_blk_mq_complete_rq() is controlled by bytes_xfered and
- * mqrq->retries. So there are only 4 possible actions here:
- * 1. do not accept the bytes_xfered value i.e. set it to zero
- * 2. change mqrq->retries to determine the number of retries
- * 3. try to reset the card
- * 4. read one sector at a time
+ * Try again to get the status. This also provides an opportunity for
+ * re-tuning.
*/
- switch (status) {
- case MMC_BLK_SUCCESS:
- case MMC_BLK_PARTIAL:
- /* Reset success, and accept bytes_xfered */
- mmc_blk_reset_success(md, type);
- break;
- case MMC_BLK_CMD_ERR:
- /*
- * For SD cards, get bytes written, but do not accept
- * bytes_xfered if that fails. For MMC cards accept
- * bytes_xfered. Then try to reset. If reset fails then
- * error out the remaining request, otherwise retry
- * once (N.B mmc_blk_reset() will not succeed twice in a
- * row).
- */
- if (mmc_card_sd(card)) {
- u32 blocks;
- int err;
+ if (err)
+ err = __mmc_send_status(card, &status, 0);

- err = mmc_sd_num_wr_blocks(card, &blocks);
- if (err)
- brq->data.bytes_xfered = 0;
- else
- brq->data.bytes_xfered = blocks << 9;
- }
- if (mmc_blk_reset(md, card->host, type))
- mqrq->retries = MMC_NO_RETRIES;
- else
- mqrq->retries = MMC_MAX_RETRIES - 1;
- break;
- case MMC_BLK_RETRY:
- /*
- * Do not accept bytes_xfered, but retry up to 5 times,
- * otherwise same as abort.
- */
- brq->data.bytes_xfered = 0;
- if (mqrq->retries < MMC_MAX_RETRIES)
- break;
- /* Fall through */
- case MMC_BLK_ABORT:
- /*
- * Do not accept bytes_xfered, but try to reset. If
- * reset succeeds, try once more, otherwise error out
- * the request.
- */
- brq->data.bytes_xfered = 0;
- if (mmc_blk_reset(md, card->host, type))
- mqrq->retries = MMC_NO_RETRIES;
- else
- mqrq->retries = MMC_MAX_RETRIES - 1;
- break;
- case MMC_BLK_DATA_ERR: {
- int err;
+ /*
+ * Nothing more to do after the number of bytes transferred has been
+ * updated and there is no card.
+ */
+ if (err && mmc_detect_card_removed(card->host))
+ return;

- /*
- * Do not accept bytes_xfered, but try to reset. If
- * reset succeeds, try once more. If reset fails with
- * ENODEV which means the partition is wrong, then error
- * out the request. Otherwise attempt to read one sector
- * at a time.
- */
- brq->data.bytes_xfered = 0;
- err = mmc_blk_reset(md, card->host, type);
- if (!err) {
- mqrq->retries = MMC_MAX_RETRIES - 1;
- break;
- }
- if (err == -ENODEV) {
- mqrq->retries = MMC_NO_RETRIES;
- break;
- }
- /* Fall through */
+ /* Try to get back to "tran" state */
+ if (!mmc_host_is_spi(mq->card->host) &&
+ (err || !mmc_blk_in_tran_state(status)))
+ err = mmc_blk_fix_state(mq->card, req);
+
+ /*
+ * Special case for SD cards where the card might record the number of
+ * blocks written.
+ */
+ if (!err && mmc_blk_cmd_started(brq) && mmc_card_sd(card) &&
+ rq_data_dir(req) == WRITE) {
+ if (mmc_sd_num_wr_blocks(card, &blocks))
+ brq->data.bytes_xfered = 0;
+ else
+ brq->data.bytes_xfered = blocks << 9;
}
- case MMC_BLK_ECC_ERR:
- /*
- * Do not accept bytes_xfered. If reading more than one
- * sector, try reading one sector at a time.
- */
- brq->data.bytes_xfered = 0;
- /* FIXME: Missing single sector read for large sector size */
- if (brq->data.blocks > 1 && !mmc_large_sector(card)) {
- /* Redo read one sector at a time */
- pr_warn("%s: retrying using single block read\n",
- req->rq_disk->disk_name);
- mmc_blk_ss_read(mq, req);
- } else {
- mqrq->retries = MMC_NO_RETRIES;
- }
- break;
- case MMC_BLK_NOMEDIUM:
- /* Do not accept bytes_xfered. Error out the request */
- brq->data.bytes_xfered = 0;
- mqrq->retries = MMC_NO_RETRIES;
- break;
- default:
- /* Do not accept bytes_xfered. Error out the request */
- brq->data.bytes_xfered = 0;
+
+ /* Reset if the card is in a bad state */
+ if (!mmc_host_is_spi(mq->card->host) &&
+ err && mmc_blk_reset(md, card->host, type)) {
+ pr_err("%s: recovery failed!\n", req->rq_disk->disk_name);
mqrq->retries = MMC_NO_RETRIES;
- pr_err("%s: Unhandled return value (%d)",
- req->rq_disk->disk_name, status);
- break;
+ return;
+ }
+
+ /*
+ * If anything was done, just return and if there is anything remaining
+ * on the request it will get requeued.
+ */
+ if (brq->data.bytes_xfered)
+ return;
+
+ /* Reset before last retry */
+ if (mqrq->retries + 1 == MMC_MAX_RETRIES)
+ mmc_blk_reset(md, card->host, type);
+
+ /* Command errors fail fast, so use all MMC_MAX_RETRIES */
+ if (brq->sbc.error || brq->cmd.error)
+ return;
+
+ /* Reduce the remaining retries for data errors */
+ if (mqrq->retries < MMC_MAX_RETRIES - MMC_DATA_RETRIES) {
+ mqrq->retries = MMC_MAX_RETRIES - MMC_DATA_RETRIES;
+ return;
+ }
+
+ /* FIXME: Missing single sector read for large sector size */
+ if (rq_data_dir(req) == READ && !mmc_large_sector(card)) {
+ /* Read one sector at a time */
+ mmc_blk_ss_read(mq, req);
+ return;
}
}

@@ -2165,16 +2192,6 @@ static inline bool mmc_blk_rq_error(struct mmc_blk_request *brq)
brq->data.error || brq->cmd.resp[0] & CMD_ERRORS;
}

-static inline bool mmc_blk_oor_valid(struct mmc_blk_request *brq)
-{
- return !!brq->mrq.sbc;
-}
-
-static inline u32 mmc_blk_stop_err_bits(struct mmc_blk_request *brq)
-{
- return mmc_blk_oor_valid(brq) ? CMD_ERRORS : CMD_ERRORS_EXCL_OOR;
-}
-
static int mmc_blk_card_busy(struct mmc_card *card, struct request *req)
{
struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);
--
1.9.1