mmc: block: Fixup busy detection while invoking stop cmd at recovery

When sending a stop command at the recovery path, use a R1B response
when the failing data request are a WRITE. Thus we also care about the
busy detection completion in this case.

For a failing READ request, we use a R1 response for the stop command,
since we don't need to care about busy detection in this case.

To align behavior between hosts supporting MMC_CAP_WAIT_WHILE_BUSY and
those who are not, we add a CMD13 polling method for the card's status.

We also respect whether the host has specified the max_busy_timeout,
which means we may fallback to CMD13 polling if the timeout is greater
than what the host are able to support.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 813ec83..452782b 100644 (file)
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -721,19 +721,6 @@ static u32 mmc_sd_num_wr_blocks(struct mmc_card *card)
        return result;
 }
 
-static int send_stop(struct mmc_card *card, u32 *status)
-{
-       struct mmc_command cmd = {0};
-       int err;
-
-       cmd.opcode = MMC_STOP_TRANSMISSION;
-       cmd.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
-       err = mmc_wait_for_cmd(card->host, &cmd, 5);
-       if (err == 0)
-               *status = cmd.resp[0];
-       return err;
-}
-
 static int get_card_status(struct mmc_card *card, u32 *status, int retries)
 {
        struct mmc_command cmd = {0};
@@ -797,6 +784,51 @@ static int card_busy_detect(struct mmc_card *card, unsigned int timeout_ms,
        return err;
 }
 
+static int send_stop(struct mmc_card *card, unsigned int timeout_ms,
+               struct request *req, int *gen_err, u32 *stop_status)
+{
+       struct mmc_host *host = card->host;
+       struct mmc_command cmd = {0};
+       int err;
+       bool use_r1b_resp = rq_data_dir(req) == WRITE;
+
+       /*
+        * Normally we use R1B responses for WRITE, but in cases where the host
+        * has specified a max_busy_timeout we need to validate it. A failure
+        * means we need to prevent the host from doing hw busy detection, which
+        * is done by converting to a R1 response instead.
+        */
+       if (host->max_busy_timeout && (timeout_ms > host->max_busy_timeout))
+               use_r1b_resp = false;
+
+       cmd.opcode = MMC_STOP_TRANSMISSION;
+       if (use_r1b_resp) {
+               cmd.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
+               cmd.busy_timeout = timeout_ms;
+       } else {
+               cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
+       }
+
+       err = mmc_wait_for_cmd(host, &cmd, 5);
+       if (err)
+               return err;
+
+       *stop_status = cmd.resp[0];
+
+       /* No need to check card status in case of READ. */
+       if (rq_data_dir(req) == READ)
+               return 0;
+
+       if (!mmc_host_is_spi(host) &&
+               (*stop_status & R1_ERROR)) {
+               pr_err("%s: %s: general error sending stop command, resp %#x\n",
+                       req->rq_disk->disk_name, __func__, *stop_status);
+               *gen_err = 1;
+       }
+
+       return card_busy_detect(card, timeout_ms, use_r1b_resp, req, gen_err);
+}
+
 #define ERR_NOMEDIUM   3
 #define ERR_RETRY      2
 #define ERR_ABORT      1
@@ -913,26 +945,21 @@ static int mmc_blk_cmd_recovery(struct mmc_card *card, struct request *req,
         */
        if (R1_CURRENT_STATE(status) == R1_STATE_DATA ||
            R1_CURRENT_STATE(status) == R1_STATE_RCV) {
-               err = send_stop(card, &stop_status);
-               if (err)
+               err = send_stop(card,
+                       DIV_ROUND_UP(brq->data.timeout_ns, 1000000),
+                       req, gen_err, &stop_status);
+               if (err) {
                        pr_err("%s: error %d sending stop command\n",
                               req->rq_disk->disk_name, err);
-
-               /*
-                * If the stop cmd also timed out, the card is probably
-                * not present, so abort.  Other errors are bad news too.
-                */
-               if (err)
+                       /*
+                        * If the stop cmd also timed out, the card is probably
+                        * not present, so abort. Other errors are bad news too.
+                        */
                        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 */