Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753478Ab0L0KSc (ORCPT ); Mon, 27 Dec 2010 05:18:32 -0500 Received: from mga01.intel.com ([192.55.52.88]:20970 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753263Ab0L0KSa (ORCPT ); Mon, 27 Dec 2010 05:18:30 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.60,234,1291622400"; d="scan'208";a="872137020" Date: Mon, 27 Dec 2010 18:13:55 +0800 From: Chuanxiao Dong To: linux-mmc@vger.kernel.org Cc: linux-kernel@vger.kernel.org, cjb@laptop.org, akpm@linux-foundation.org Subject: [PATCH v6 2/3]mmc: do HW reset if eMMC card occurs timeout error Message-ID: <20101227101355.GC20143@intel.com> Reply-To: Chuanxiao Dong MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5141 Lines: 159 Two new callbacks were added in mmc_bus_ops to implement this. hwreset_emmc: trigger a RST_n signal for host to reset card. reinit_emmc: reinitialize eMMC card after hardware reset occurs. MMC core layer will check whether occurs a timeout error in the new added function mmc_handle_timeout_error. Signed-off-by: Chuanxiao Dong --- drivers/mmc/card/block.c | 10 +++++++++ drivers/mmc/core/core.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++ drivers/mmc/core/core.h | 26 ++++++++++++++++++++++++ include/linux/mmc/core.h | 1 + 4 files changed, 85 insertions(+), 0 deletions(-) diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index 217f820..ba9614d 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -424,6 +424,16 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req) mmc_wait_for_req(card->host, &brq.mrq); + /* Check if need to do HW reset */ + if (brq.cmd.error) + mmc_handle_timeout_error(card->host, brq.cmd.error); + + if (brq.data.error) + mmc_handle_timeout_error(card->host, brq.data.error); + + if (brq.stop.error) + mmc_handle_timeout_error(card->host, brq.stop.error); + mmc_queue_bounce_post(mq); /* diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index a8e89f3..795bd81 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -83,6 +83,52 @@ static void mmc_flush_scheduled_work(void) } /** + * mmc_handle_timeout_error - handle timeout errors occurs by card + * @host: MMC host used to handle error + * @error: error condition + * + * check whether there is a command or data timeout error occurred, + * if so, reset and reinit eMMC card if card has such capability. + * + * In this function, driver will do follow things: + * 1. let host controller do a specific hardware reset for eMMC + * card (trigger RST_n signal). + * 2. after reset done, reinit eMMC card. + */ +void mmc_handle_timeout_error(struct mmc_host *host, int error) +{ + struct mmc_card *card = host->card; + + /* + * If error condition is not timeout, do nothing + */ + if (error != -ETIMEDOUT) + return; + /* + * make sure card is not NULL + * make sure mmc_card has HW reset capability + */ + if (!card || !card->ext_csd.rst) + return; + + /* check whether host has such callback */ + if (!host->bus_ops->hwreset_emmc || + !host->bus_ops->reinit_emmc) + return; + + /* + * if there occurs any timeout error, HW reset + * eMMC card and reinit again. + */ + if (host->bus_ops->hwreset_emmc(host)) + pr_warn("MMC card reset failed\n"); + else + if (host->bus_ops->reinit_emmc(host)) + pr_warn("MMC card reinit failed\n"); +} +EXPORT_SYMBOL(mmc_handle_timeout_error); + +/** * mmc_request_done - finish processing an MMC request * @host: MMC host which completed request * @mrq: MMC request which request @@ -1341,6 +1387,8 @@ static int mmc_do_erase(struct mmc_card *card, unsigned int from, if (err) { printk(KERN_ERR "mmc_erase: erase error %d, status %#x\n", err, cmd.resp[0]); + /* Before return, check whether can do a HW reset */ + mmc_handle_timeout_error(card->host, cmd.error); err = -EIO; goto out; } diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h index 026c975..09b6c54 100644 --- a/drivers/mmc/core/core.h +++ b/drivers/mmc/core/core.h @@ -24,6 +24,32 @@ struct mmc_bus_ops { int (*resume)(struct mmc_host *); int (*power_save)(struct mmc_host *); int (*power_restore)(struct mmc_host *); + /* + * New added callback + * This function is used to reinitialize eMMC card after eMMC card been + * reset. + * + * Note 1: before calling this, mmc_claim_host is needed. After finish + * this calling, mmc_release_host is needed. + * + * return value: + * 0 - successfully reinit card + * other - failed to reinit + */ + int (*reinit_emmc)(struct mmc_host *); + /* + * New added callback + * This function is used to trigger RST_n signal to reset eMMC card as + * eMMC4.4 spec recommended. + * + * Note 1: this function may sleep since delay is needed when pull + * up/down GPIO line. + * + * return value: + * 0 - successfully reset eMMC card + * other - failed to reset eMMC card + */ + int (*hwreset_emmc)(struct mmc_host *); }; void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops); diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h index 64e013f..115d589 100644 --- a/include/linux/mmc/core.h +++ b/include/linux/mmc/core.h @@ -131,6 +131,7 @@ struct mmc_request { struct mmc_host; struct mmc_card; +extern void mmc_handle_timeout_error(struct mmc_host *, int); extern void mmc_wait_for_req(struct mmc_host *, struct mmc_request *); extern int mmc_wait_for_cmd(struct mmc_host *, struct mmc_command *, int); extern int mmc_wait_for_app_cmd(struct mmc_host *, struct mmc_card *, -- 1.6.6.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/