From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adrian Hunter Subject: Re: [RESEND PATCH V3] mmc: core: Detect card removal on I/O error Date: Fri, 03 Feb 2012 14:52:37 +0200 Message-ID: <4F2BD895.2030301@intel.com> References: <1328261593-6112-1-git-send-email-ulf.hansson@stericsson.com> <4F2BC790.3090304@intel.com> <4F2BD00C.8040703@stericsson.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mga03.intel.com ([143.182.124.21]:16649 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753848Ab2BCMxs (ORCPT ); Fri, 3 Feb 2012 07:53:48 -0500 In-Reply-To: <4F2BD00C.8040703@stericsson.com> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Ulf Hansson Cc: "linux-mmc@vger.kernel.org" , Chris Ball , Per FORLIN , Johan RUDHOLM , Lee Jones On 03/02/12 14:16, Ulf Hansson wrote: > Adrian Hunter wrote: >> On 03/02/12 11:33, Ulf Hansson wrote: >>> To prevent I/O as soon as possible at card removal, a new >>> detect work is re-scheduled without a delay to let a rescan >>> remove the card device as soon a possible. >>> >>> Additionally, MMC_CAP2_DETECT_ON_ERR can now be used to handle >>> "slowly" removed cards that a scheduled detect work did not >>> detect as removed. To prevent further I/O requests for these >>> lingering removed cards, check if card has been removed and then >>> schedule a detect work to properly remove it. >>> >>> Signed-off-by: Ulf Hansson >>> --- >>> >>> Changes in v3: >>> - Check for card is NULL and minor code simplifications. >>> >>> Changes in v2: >>> - Updated according to review comments. >>> - Merging two patches for this feature into one. >>> >>> --- >>> drivers/mmc/core/core.c | 24 +++++++++++++++++++++--- >>> include/linux/mmc/host.h | 1 + >>> 2 files changed, 22 insertions(+), 3 deletions(-) >>> >>> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c >>> index bec0bf2..9645e8c 100644 >>> --- a/drivers/mmc/core/core.c >>> +++ b/drivers/mmc/core/core.c >>> @@ -2077,18 +2077,36 @@ int _mmc_detect_card_removed(struct mmc_host *host) >>> int mmc_detect_card_removed(struct mmc_host *host) >>> { >>> struct mmc_card *card = host->card; >>> + int ret; >>> >>> WARN_ON(!host->claimed); >>> + >>> + if (!card) >>> + return 1; >>> + >>> + ret = mmc_card_removed(card); >>> /* >>> * The card will be considered unchanged unless we have been asked to >>> * detect a change or host requires polling to provide card detection. >>> */ >>> - if (card && !host->detect_change && !(host->caps & MMC_CAP_NEEDS_POLL)) >>> - return mmc_card_removed(card); >>> + if (!host->detect_change && !(host->caps & MMC_CAP_NEEDS_POLL) && >>> + !(host->caps2 & MMC_CAP2_DETECT_ON_ERR)) >>> + return ret; >>> >>> host->detect_change = 0; >>> + if (!ret) { >>> + ret = _mmc_detect_card_removed(host); >>> + if (ret) { >> >> Please make this >> >> if (ret && (host->caps2 & MMC_CAP2_DETECT_ON_ERR)) >> >> because if rescan is already running this will needlessly queue >> another one. >> > > It wont queue another one. It will cancel a work which likely has been > scheduled to be executed within several ms later. Then it will re-schedule a > new one without any delay since there is no need to wait, when we already > know that the card has been removed. It won't cancel a rescan that is already running (waiting to claim the host for example) but it will queue another one. Hence the comment. > > >>> + /* >>> + * Schedule a detect work as soon as possible to let a >>> + * rescan handle the card removal. >>> + */ >>> + cancel_delayed_work(&host->detect); >>> + mmc_detect_change(host, 0); >>> + } >>> + } >>> >>> - return _mmc_detect_card_removed(host); >>> + return ret; >>> } >>> EXPORT_SYMBOL(mmc_detect_card_removed); >>> >>> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h >>> index dd13e05..368a2b9 100644 >>> --- a/include/linux/mmc/host.h >>> +++ b/include/linux/mmc/host.h >>> @@ -257,6 +257,7 @@ struct mmc_host { >>> #define MMC_CAP2_HS200_1_2V_SDR (1 << 6) /* can support */ >>> #define MMC_CAP2_HS200 (MMC_CAP2_HS200_1_8V_SDR | \ >>> MMC_CAP2_HS200_1_2V_SDR) >>> +#define MMC_CAP2_DETECT_ON_ERR (1 << 7) /* On I/O err check card >>> removal */ >>> >>> mmc_pm_flag_t pm_caps; /* supported pm features */ >>> unsigned int power_notify_type; >> >> > >