在 2016/8/24 17:30, Ulf Hansson 写道:
On 24 August 2016 at 09:58, Shawn Lin <shawn.lin@xxxxxxxxxxxxxx> wrote: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. 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_PACKED_NONE and MMC_BLK_PACKED_CMD. By doing this, we could fall back to non-packed request if finding null packed, though it's impossible theoretically. Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx> --- Changes in v2: - remove BUG_ON and add fallback for packed instead of panic it. drivers/mmc/card/block.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index 48a5dd7..c7a9b28 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -1673,6 +1673,18 @@ 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; @@ -1781,8 +1793,6 @@ 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; @@ -1886,8 +1896,6 @@ 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) { -- 2.3.7This is step in the right direction, although there are still some BUG_ONs() for the packed command path. Could you please have look and remove all of them?
yup, I will try to remove all of them when I respin v3. Thansk.
Kind regards Uffe
-- Best Regards Shawn Lin -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
