mmc: block: prevent propagating R1_OUT_OF_RANGE for open-ending mode

We to some extent should tolerate R1_OUT_OF_RANGE for open-ending
mode as it is expected behaviour and most of the backup partition
tables should be located near some of the last blocks which will
always make open-ending read exceed the capacity of cards.

Fixes: 9820a5b11101 ("mmc: core: for data errors, take response of stop cmd into account")
Fixes: a04e6bae9e6f ("mmc: core: check also R1 response for stop commands")
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index f1bbfd3..80d1ec6 100644 (file)
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -1371,12 +1371,46 @@ static inline void mmc_apply_rel_rw(struct mmc_blk_request *brq,
         R1_CC_ERROR |          /* Card controller error */             \
         R1_ERROR)              /* General/unknown error */
 
-static bool mmc_blk_has_cmd_err(struct mmc_command *cmd)
+static void mmc_blk_eval_resp_error(struct mmc_blk_request *brq)
 {
-       if (!cmd->error && cmd->resp[0] & CMD_ERRORS)
-               cmd->error = -EIO;
+       u32 val;
 
-       return cmd->error;
+       /*
+        * Per the SD specification(physical layer version 4.10)[1],
+        * section 4.3.3, it explicitly states that "When the last
+        * block of user area is read using CMD18, the host should
+        * ignore OUT_OF_RANGE error that may occur even the sequence
+        * is correct". And JESD84-B51 for eMMC also has a similar
+        * statement on section 6.8.3.
+        *
+        * Multiple block read/write could be done by either predefined
+        * method, namely CMD23, or open-ending mode. For open-ending mode,
+        * we should ignore the OUT_OF_RANGE error as it's normal behaviour.
+        *
+        * However the spec[1] doesn't tell us whether we should also
+        * ignore that for predefined method. But per the spec[1], section
+        * 4.15 Set Block Count Command, it says"If illegal block count
+        * is set, out of range error will be indicated during read/write
+        * operation (For example, data transfer is stopped at user area
+        * boundary)." In another word, we could expect a out of range error
+        * in the response for the following CMD18/25. And if argument of
+        * CMD23 + the argument of CMD18/25 exceed the max number of blocks,
+        * we could also expect to get a -ETIMEDOUT or any error number from
+        * the host drivers due to missing data response(for write)/data(for
+        * read), as the cards will stop the data transfer by itself per the
+        * spec. So we only need to check R1_OUT_OF_RANGE for open-ending mode.
+        */
+
+       if (!brq->stop.error) {
+               bool oor_with_open_end;
+               /* If there is no error yet, check R1 response */
+
+               val = brq->stop.resp[0] & CMD_ERRORS;
+               oor_with_open_end = val & R1_OUT_OF_RANGE && !brq->mrq.sbc;
+
+               if (val && !oor_with_open_end)
+                       brq->stop.error = -EIO;
+       }
 }
 
 static enum mmc_blk_status mmc_blk_err_check(struct mmc_card *card,
@@ -1400,8 +1434,11 @@ static enum mmc_blk_status mmc_blk_err_check(struct mmc_card *card,
         * stop.error indicates a problem with the stop command.  Data
         * may have been transferred, or may still be transferring.
         */
-       if (brq->sbc.error || brq->cmd.error || mmc_blk_has_cmd_err(&brq->stop) ||
-           brq->data.error) {
+
+       mmc_blk_eval_resp_error(brq);
+
+       if (brq->sbc.error || brq->cmd.error ||
+           brq->stop.error || brq->data.error) {
                switch (mmc_blk_cmd_recovery(card, req, brq, &ecc_err, &gen_err)) {
                case ERR_RETRY:
                        return MMC_BLK_RETRY;