On 28 June 2011 10:11, Per Forlin per.forlin@linaro.org wrote:
Change mmc_blk_issue_rw_rq() to become asynchronous. The execution flow looks like this: The mmc-queue calls issue_rw_rq(), which sends the request to the host and returns back to the mmc-queue. The mmc-queue calls issue_rw_rq() again with a new request. This new request is prepared, in isuue_rw_rq(), then it waits for the active request to complete before pushing it to the host. When to mmc-queue is empty it will call isuue_rw_rq() with req=NULL to finish off the active request without starting a new request.
Signed-off-by: Per Forlin per.forlin@linaro.org
drivers/mmc/card/block.c | 80 +++++++++++++++++++++++++++++++++++++-------- drivers/mmc/card/queue.c | 17 +++++++--- drivers/mmc/card/queue.h | 1 + 3 files changed, 78 insertions(+), 20 deletions(-)
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index 7ed2c68..825741e 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c
...
@@ -1066,6 +1085,13 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req) ret = __blk_end_request(req, 0, brq->data.bytes_xfered); spin_unlock_irq(&md->lock);
- if (status == MMC_BLK_SUCCESS && ret) {
- /* If this happen it is a bug */
- printk(KERN_ERR "%s BUG rq_tot %d d_xfer %d\n",
- __func__, blk_rq_bytes(req),
- brq->data.bytes_xfered);
+ rqc = NULL If there is a new request (rqc != NULL) it will already be started when reaching this point. If rqc is set it will be started again at start_new_req.
I wonder if this paranoia check is necessary. If "status == MMC_BLK_SUCCESS" all bytes are transferred and no error returned from mmc layer. __blk_end_request would always return 0 in this case, please comment if you disagree.
...
- start_new_req:
- if (rqc) {
- mmc_blk_rw_rq_prep(mq->mqrq_cur, card, 0, mq);
- mmc_start_req(card->host, &mq->mqrq_cur->mmc_active, NULL);
- }
return 0; }
/Per