Merge "mmc: core: Restrict number of request in driver queue"

static int mmc_blk_cqe_issue_rw_rq(struct mmc_queue *mq, struct request *req)

{

	struct mmc_queue_req *mqrq = req_to_mmc_queue_req(req);

	struct mmc_card *card = mq->card;

	struct mmc_host *host = card->host;

	int err = 0;

	mmc_blk_data_prep(mq, mqrq, 0, NULL, NULL);

	mmc_deferred_scaling(mq->card->host);

	mmc_cqe_clk_scaling_start_busy(mq, mq->card->host, true);

	/*

	 * When voltage corner in LSVS on low load scenario and

	 * there is sudden burst of requests device queue all

	 * slots are filled and it is needed to wait till all

	 * requests are completed to scale up frequency. This

	 * is leading to delay in scaling and impacting performance.

	 * Fix this issue by only allowing one request in request queue

	 * when device is running with lower speed mode.

	 */

	if (host->clk_scaling.state == MMC_LOAD_LOW) {

		err = host->cqe_ops->cqe_wait_for_idle(host);

		if (err) {

			pr_err("%s: %s: CQE went in recovery path.\n",

				mmc_hostname(host), __func__);

			goto stop_scaling;

		}

	}

	err =  mmc_blk_cqe_start_req(mq->card->host, &mqrq->brq.mrq);

stop_scaling:

	if (err)

		mmc_cqe_clk_scaling_stop_busy(mq->card->host, true, false);