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Commit 29eba0a6 authored by Adrian Hunter's avatar Adrian Hunter Committed by Veerabhadrarao Badiganti
Browse files

mmc: core: Add support for re-tuning before each request 



At the start of each request, re-tune if needed and
then hold off re-tuning again until the request is done.

Note that though there is one function that starts
requests (mmc_start_request) there are two that wait for
the request to be done (mmc_wait_for_req_done and
mmc_wait_for_data_req_done).  Also note that
mmc_wait_for_data_req_done can return even when the
request is not done (which allows the block driver
to prepare a newly arrived request while still
waiting for the previous request).

This patch ensures re-tuning is held for the duration
of a request.  Subsequent patches will also hold
re-tuning at other times when it might cause a
conflict.

In addition, possibly a command is failing because
re-tuning is needed. Use mmc_retune_recheck() to check
re-tuning. At that point re-tuning is held, at least by
the request, so mmc_retune_recheck() flags host->retune_now
if the hold count is 1.

Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Git-commit: 90a81489b0a9d7b56df2dcf68498fd3a03deb354
Git-repo: git://git.linaro.org/people/ulf.hansson/mmc.git


Change-Id: Ib5d25e017657eb7dfab47c869ce7a3b23be5d1e5
Signed-off-by: default avatarVeerabhadrarao Badiganti <vbadigan@codeaurora.org>
parent 8e19c8cb

drivers/mmc/core/core.c

+27 −7
Original line number Diff line number Diff line
@@ -961,6 +961,21 @@ void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq) 


EXPORT_SYMBOL(mmc_request_done);



static void __mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)

{

	int err;



	/* Assumes host controller has been runtime resumed by mmc_claim_host */

	err = mmc_retune(host);

	if (err) {

		mrq->cmd->error = err;

		mmc_request_done(host, mrq);

		return;

	}



	host->ops->request(host, mrq);

}



static void

mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)

{
@@ -968,6 +983,7 @@ mmc_start_request(struct mmc_host *host, struct mmc_request *mrq) 
	unsigned int i, sz;

	struct scatterlist *sg;

#endif

	mmc_retune_hold(host);



	if (mrq->sbc) {

		pr_debug("<%s: starting CMD%u arg %08x flags %08x>\n",
@@ -1032,7 +1048,7 @@ mmc_start_request(struct mmc_host *host, struct mmc_request *mrq) 
		mmc_clk_scaling_start_busy(host, true);

	}



	host->ops->request(host, mrq);

	__mmc_start_request(host, mrq);

}



static void mmc_start_cmdq_request(struct mmc_host *host,
@@ -1353,22 +1369,22 @@ static int mmc_wait_for_data_req_done(struct mmc_host *host, 
							    host->areq);

				break; /* return err */

			} else {

				mmc_retune_recheck(host);

				pr_info("%s: req failed (CMD%u): %d, retrying...\n",

					mmc_hostname(host),

					cmd->opcode, cmd->error);

				cmd->retries--;

				cmd->error = 0;

				host->ops->request(host, mrq);

				__mmc_start_request(host, mrq);

				continue; /* wait for done/new event again */

			}

		} else if (context_info->is_new_req) {

			context_info->is_new_req = false;

			if (!next_req) {

				err = MMC_BLK_NEW_REQUEST;

				break; /* return err */

			}

			if (!next_req)

				return MMC_BLK_NEW_REQUEST;

		}

	}

	mmc_retune_release(host);

	return err;

}
@@ -1403,12 +1419,16 @@ static void mmc_wait_for_req_done(struct mmc_host *host, 
		    mmc_card_removed(host->card))

			break;



		mmc_retune_recheck(host);



		pr_debug("%s: req failed (CMD%u): %d, retrying...\n",

			 mmc_hostname(host), cmd->opcode, cmd->error);

		cmd->retries--;

		cmd->error = 0;

		host->ops->request(host, mrq);

		__mmc_start_request(host, mrq);

	}



	mmc_retune_release(host);

}



/**