mmc: block: add handling for two parallel block requests in issue_rw_rq
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 issue_rw_rq(), then it waits for
the active request to complete before pushing it to the host.
* When the mmc-queue is empty it will call issue_rw_rq() with a NULL
req to finish off the active request without starting a new request.
Signed-off-by: Per Forlin <per.forlin@linaro.org>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Venkatraman S <svenkatr@ti.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Konstantin Dorfman <kdorfman@codeaurora.org>
diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index 2d2576c..2a9d62a 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -57,6 +57,7 @@
down(&mq->thread_sem);
do {
+ struct mmc_queue_req *tmp;
req = NULL; /* Must be set to NULL at each iteration */
spin_lock_irq(q->queue_lock);
@@ -65,7 +66,10 @@
mq->mqrq_cur->req = req;
spin_unlock_irq(q->queue_lock);
- if (!req) {
+ if (req || mq->mqrq_prev->req) {
+ set_current_state(TASK_RUNNING);
+ mq->issue_fn(mq, req);
+ } else {
if (kthread_should_stop()) {
set_current_state(TASK_RUNNING);
break;
@@ -73,10 +77,14 @@
up(&mq->thread_sem);
schedule();
down(&mq->thread_sem);
- continue;
}
- set_current_state(TASK_RUNNING);
- mq->issue_fn(mq, req);
+
+ /* Current request becomes previous request and vice versa. */
+ mq->mqrq_prev->brq.mrq.data = NULL;
+ mq->mqrq_prev->req = NULL;
+ tmp = mq->mqrq_prev;
+ mq->mqrq_prev = mq->mqrq_cur;
+ mq->mqrq_cur = tmp;
} while (1);
up(&mq->thread_sem);
@@ -102,7 +110,7 @@
return;
}
- if (!mq->mqrq_cur->req)
+ if (!mq->mqrq_cur->req && !mq->mqrq_prev->req)
wake_up_process(mq->thread);
}