Hi Saugata,
Could you check the comment below?
Friday, June 29, 2012, Saugata Das <saugata.das@xxxxxxxxxx> wrote:
> From: Saugata Das <saugata.das@xxxxxxxxxx>
>
> In 512B disable emulation patch, a check is done to ensure that size
> of the data is multiple of 4KB. However, the check is done with
> brq->data.blocks, which is not initialized at the point of check.
> This is now changed to blk_rq_sectors.
>
> Signed-off-by: Saugata Das <saugata.das@xxxxxxxxxx>
> ---
> drivers/mmc/card/block.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
> index d628c5d..ee8b3d6 100644
> --- a/drivers/mmc/card/block.c
> +++ b/drivers/mmc/card/block.c
> @@ -1296,7 +1296,7 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc)
> * When 4KB native sector is enabled, only 8 blocks
> * multiple read or write is allowed
> */
> - if ((brq->data.blocks & 0x07) &&
> + if ((blk_rq_sectors(req) & 0x07) &&
> (card->ext_csd.data_sector_size == 4096)) {
> pr_err("%s: Transfer size is not 4KB sector size aligned\n",
> req->rq_disk->disk_name);
In current error handling, multiple block read can be retried using single block read
with disable_multi. Then 4KB alignment will be broken.
Also, there is some conditions to modify the number of blocks in mmc_blk_rw_rq_prep.
That means the alignment of blocks can be changed after mmc_blk_rw_rq_prep.
It needs to be considered.
And I have a question.
Spec mentioned that arguments for read commands (CMD17/18) shall always be aligned to 8(4KB)
in Native 4KB sector. In current implementation CMD17/18 is only used when data.blocks is 1.
If data.blocks is 8 in Native 4KB sector, then CMD17/18 should be taken instead of CMD24/25?
Thanks,
Seungwon Jeon
> --
> 1.7.4.3
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