From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adrian Hunter Subject: [PATCH V2 03/15] mmc: core: Add support for re-tuning before each request Date: Thu, 29 Jan 2015 11:00:18 +0200 Message-ID: <1422522030-17793-4-git-send-email-adrian.hunter@intel.com> References: <1422522030-17793-1-git-send-email-adrian.hunter@intel.com> Return-path: Received: from mga09.intel.com ([134.134.136.24]:47307 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758273AbbA2JCh (ORCPT ); Thu, 29 Jan 2015 04:02:37 -0500 In-Reply-To: <1422522030-17793-1-git-send-email-adrian.hunter@intel.com> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Ulf Hansson , Chris Ball Cc: linux-mmc , Aaron Lu , Philip Rakity , Girish K S , Al Cooper , Arend van Spriel 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. Signed-off-by: Adrian Hunter --- drivers/mmc/core/core.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index e9ab5ff..6dad56d 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -192,9 +192,21 @@ static int mmc_start_request(struct mmc_host *host, struct mmc_request *mrq) unsigned int i, sz; struct scatterlist *sg; #endif + int err; + + mmc_retune_hold(host); + if (mmc_card_removed(host->card)) return -ENOMEDIUM; + err = mmc_retune_recheck(host); + if (err) { + /* Retry path expects the clock to be held */ + if (mrq->cmd->retries) + mmc_host_clk_hold(host); + return err; + } + if (mrq->sbc) { pr_debug("<%s: starting CMD%u arg %08x flags %08x>\n", mmc_hostname(host), mrq->sbc->opcode, @@ -427,12 +439,11 @@ static int mmc_wait_for_data_req_done(struct mmc_host *host, } } 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; } @@ -473,6 +484,8 @@ static void mmc_wait_for_req_done(struct mmc_host *host, cmd->error = 0; host->ops->request(host, mrq); } + + mmc_retune_release(host); } /** -- 1.9.1