mmc: block: remove the check of packed for packed request routine

packed should always exist without calling its cleanup function
explicitly. Moreover, we have use it when preparing packed list.
So I don't believe we should ever fall into this check again when
doing mmc_blk_packed_hdr_wrq_prep or mmc_blk_end_packed_req,etc.
And the code of mmc_blk_end_packed_req is trying to use packed before
checking it which makes it quite weird. This patch is trying to
remove these two checks and move it to the mmc_blk_prep_packed_list.
If we find packed is null, then we should never use MMC_BLK_PACKED_CMD.
By doing this, we could fall back to non-packed request if finding null
packed, though it's impossible theoretically.

After removing these two BUG_ONs, we also remove all other similar
checks within the routine of mmc_blk_issue_rw_rq which checks the
error handling of packed request.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 2206d44..74c7625 100644 (file)
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -142,8 +142,6 @@ static inline void mmc_blk_clear_packed(struct mmc_queue_req *mqrq)
 {
        struct mmc_packed *packed = mqrq->packed;
 
-       BUG_ON(!packed);
-
        mqrq->cmd_type = MMC_PACKED_NONE;
        packed->nr_entries = MMC_PACKED_NR_ZERO;
        packed->idx_failure = MMC_PACKED_NR_IDX;
@@ -1443,8 +1441,6 @@ static int mmc_blk_packed_err_check(struct mmc_card *card,
        int err, check, status;
        u8 *ext_csd;
 
-       BUG_ON(!packed);
-
        packed->retries--;
        check = mmc_blk_err_check(card, areq);
        err = get_card_status(card, &status, 0);
@@ -1673,6 +1669,18 @@ static u8 mmc_blk_prep_packed_list(struct mmc_queue *mq, struct request *req)
        u8 max_packed_rw = 0;
        u8 reqs = 0;
 
+       /*
+        * We don't need to check packed for any further
+        * operation of packed stuff as we set MMC_PACKED_NONE
+        * and return zero for reqs if geting null packed. Also
+        * we clean the flag of MMC_BLK_PACKED_CMD to avoid doing
+        * it again when removing blk req.
+        */
+       if (!mqrq->packed) {
+               md->flags &= (~MMC_BLK_PACKED_CMD);
+               goto no_packed;
+       }
+
        if (!(md->flags & MMC_BLK_PACKED_CMD))
                goto no_packed;
 
@@ -1782,8 +1790,6 @@ static void mmc_blk_packed_hdr_wrq_prep(struct mmc_queue_req *mqrq,
        u8 hdr_blocks;
        u8 i = 1;
 
-       BUG_ON(!packed);
-
        mqrq->cmd_type = MMC_PACKED_WRITE;
        packed->blocks = 0;
        packed->idx_failure = MMC_PACKED_NR_IDX;
@@ -1887,8 +1893,6 @@ static int mmc_blk_end_packed_req(struct mmc_queue_req *mq_rq)
        int idx = packed->idx_failure, i = 0;
        int ret = 0;
 
-       BUG_ON(!packed);
-
        while (!list_empty(&packed->list)) {
                prq = list_entry_rq(packed->list.next);
                if (idx == i) {
@@ -1917,8 +1921,6 @@ static void mmc_blk_abort_packed_req(struct mmc_queue_req *mq_rq)
        struct request *prq;
        struct mmc_packed *packed = mq_rq->packed;
 
-       BUG_ON(!packed);
-
        while (!list_empty(&packed->list)) {
                prq = list_entry_rq(packed->list.next);
                list_del_init(&prq->queuelist);
@@ -1935,8 +1937,6 @@ static void mmc_blk_revert_packed_req(struct mmc_queue *mq,
        struct request_queue *q = mq->queue;
        struct mmc_packed *packed = mq_rq->packed;
 
-       BUG_ON(!packed);
-
        while (!list_empty(&packed->list)) {
                prq = list_entry_rq(packed->list.prev);
                if (prq->queuelist.prev != &packed->list) {