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In-Reply-To: <20101123084510.GE17754@intel.com>
References: <20101123084510.GE17754@intel.com>
Date: Wed, 24 Nov 2010 13:07:46 +0900
Message-ID: <AANLkTinF3+nUb8ugttyw-A_ss8cyX1iHFzG6bLdGf5d6@mail.gmail.com>
Subject: Re: [PATCH v1 4/4]use HPI to interrupt background operations
From: Kyungmin Park <kmpark@infradead.org>
To: Chuanxiao Dong <chuanxiao.dong@intel.com>
Cc: linux-mmc@vger.kernel.org, cjb@laptop.org, linux-kernel@vger.kernel.org,
        alan@linux.intel.com, arjan@linux.intel.com, hang.yuan@intel.com
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On Tue, Nov 23, 2010 at 5:45 PM, Chuanxiao Dong
<chuanxiao.dong@intel.com> wrote:
> From 8d2cf8e4b890a3ef0c7b63da57b8b184ab64725d Mon Sep 17 00:00:00 2001
> From: Chuanxiao Dong <chuanxiao.dong@intel.com>
> Date: Tue, 23 Nov 2010 12:01:58 +0800
> Subject: [PATCH 4/4] mmc: Add HPI operation to interrupt BKOPS
>
> Before start a new user request, driver need to wait until the
> BKOPS finished, or use HPI to interrupt the BKOPS since user request
> has a higher priority than BKOPS.
>
> This patch implemented using HPI to interrupt BKOPS if eMMC card
> supports HPI.
>
> Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com>
> ---
> ?drivers/mmc/core/core.c | ? 51 ++++++++++++++++++++++++++++++++++++++++++++++-
> ?1 files changed, 50 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index 6891169..644ce9d 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -202,6 +202,50 @@ static void mmc_wait_done(struct mmc_request *mrq)
> ?}
>
> ?/**
> + * ? ? mmc_issue_hpi_cmd - start a hpi to interrupt background
> + * ? ? operations
> + * ? ? @card: MMC card need to interrupt
> + *
> + * ?start MMC_SEND_STATUS/MMC_STOP_TRANSMISSION to stop the
> + * ?background operations.
> + *
> + * ?return value:
> + * ?0: successfully interrupt BKOPS
> + * ?-EINVAL: HPI command invalid
> + * ?-EIO: failed when interrupt BKOPS
> + */
> +static int mmc_issue_hpi_cmd(struct mmc_card *card)
> +{
> + ? ? ? struct mmc_command cmd;
> + ? ? ? unsigned int opcode;
> + ? ? ? unsigned int flags;
> + ? ? ? int err;
> +
> + ? ? ? opcode = card->ext_csd.hpi_cmd;
> + ? ? ? if (opcode == MMC_STOP_TRANSMISSION)
> + ? ? ? ? ? ? ? flags = MMC_RSP_R1B | MMC_CMD_AC;
> + ? ? ? else if (opcode == MMC_SEND_STATUS)
> + ? ? ? ? ? ? ? flags = MMC_RSP_R1 | MMC_CMD_AC;
> + ? ? ? else
> + ? ? ? ? ? ? ? return -EINVAL;
> +
> + ? ? ? memset(&cmd, 0, sizeof(struct mmc_command));
> + ? ? ? cmd.opcode = opcode;
> + ? ? ? cmd.arg = card->rca << 16 | 1;
Maybe missing set the flags;
            cmd.flags = flags;

Thank you,
Kyungmin Park
> + ? ? ? err = mmc_wait_for_cmd(card->host, &cmd, 0);
> + ? ? ? if (err || (cmd.resp[0] & 0xFDF92000)) {
> + ? ? ? ? ? ? ? printk(KERN_ERR "error %d requesting status %#x\n",
> + ? ? ? ? ? ? ? ? ? ? ? err, cmd.resp[0]);
> + ? ? ? ? ? ? ? /*
> + ? ? ? ? ? ? ? ?* abandon this BKOPS, let block layer handle
> + ? ? ? ? ? ? ? ?* this
> + ? ? ? ? ? ? ? ?*/
> + ? ? ? ? ? ? ? return -EIO;
> + ? ? ? }
> + ? ? ? return 0;
> +}
> +
> +/**
> ?* ? ? mmc_wait_for_bkops- start a bkops check and wait for
> ?* ? ? completion
> ?* ? ? @card: MMC card need to check
> @@ -224,9 +268,14 @@ retry:
>
> ? ? ? ?if (card->ext_csd.hpi_en) {
> ? ? ? ? ? ? ? ?/*
> - ? ? ? ? ? ? ? ?* TODO
> ? ? ? ? ? ? ? ? * HPI to interrupt BKOPS if supported
> ? ? ? ? ? ? ? ? */
> + ? ? ? ? ? ? ? err = mmc_issue_hpi_cmd(card);
> + ? ? ? ? ? ? ? if (err == -EINVAL) {
> + ? ? ? ? ? ? ? ? ? ? ? /* disable HPI feature */
> + ? ? ? ? ? ? ? ? ? ? ? card->ext_csd.hpi_en = 0;
> + ? ? ? ? ? ? ? ? ? ? ? goto retry;
> + ? ? ? ? ? ? ? }
> ? ? ? ?} else {
> ? ? ? ? ? ? ? ?memset(&cmd, 0, sizeof(struct mmc_command));
>
> --
> 1.6.6.1
>
> --
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