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Date: Fri, 2 Apr 2021 00:48:23 +0200
From: Ulf Hansson <ulf.hansson@...aro.org>
To: Bean Huo <huobean@...il.com>
Cc: "Shimoda, Yoshihiro" <yoshihiro.shimoda.uh@...esas.com>,
Wolfram Sang <wsa+renesas@...g-engineering.com>,
Adrian Hunter <adrian.hunter@...el.com>,
linux-mmc <linux-mmc@...r.kernel.org>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
Bean Huo <beanhuo@...ron.com>
Subject: Re: [PATCH v2 1/2] mmc: core: Let sanitize timeout readable/writable
via sysfs
On Thu, 1 Apr 2021 at 15:29, Bean Huo <huobean@...il.com> wrote:
>
> From: Bean Huo <beanhuo@...ron.com>
>
> As the density increases, the 4-minute timeout value for
> sanitize is no longer feasible. At the same time, devices
> of different densities have different timeout values, and it is
> difficult to obtain a unified standard timeout value. Therefore,
> it is better to let the user explicitly change sanitize timeout
> value according to the eMMC density on the board.
This makes sense. The current timeout in the mmc core isn't good
enough. However, I think there is a better option than inventing a
sysfs node to allow userspace to specify the timeout.
First, we have the card quirks that the mmc core uses to allow us to
modify a common behaviour (in this case timeouts values for sanitize
operations). This can be used to enforce a specific timeout for the
eMMC card. I think this should take precedence over anything else.
Second, the ioctl command allows you to specify a specific command
timeout in the struct mmc_ioc_cmd (.cmd_timeout_ms). If this is
specified from user space we could forward it to mmc_santize() and use
that rather than the default MMC_SANITIZE_TIMEOUT_MS.
Would this satisfy your needs?
Kind regards
Uffe
>
> Signed-off-by: Bean Huo <beanhuo@...ron.com>
> ---
> drivers/mmc/core/mmc.c | 34 ++++++++++++++++++++++++++++++++++
> drivers/mmc/core/mmc_ops.c | 3 +--
> include/linux/mmc/card.h | 1 +
> 3 files changed, 36 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index 8741271d3971..3885cc1780ac 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -28,6 +28,7 @@
>
> #define DEFAULT_CMD6_TIMEOUT_MS 500
> #define MIN_CACHE_EN_TIMEOUT_MS 1600
> +#define MMC_SANITIZE_TIMEOUT_MS (240 * 1000) /* 240s */
>
> static const unsigned int tran_exp[] = {
> 10000, 100000, 1000000, 10000000,
> @@ -835,6 +836,37 @@ static ssize_t mmc_dsr_show(struct device *dev,
>
> static DEVICE_ATTR(dsr, S_IRUGO, mmc_dsr_show, NULL);
>
> +static ssize_t sanitize_timeout_ms_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct mmc_card *card = mmc_dev_to_card(dev);
> +
> + return sysfs_emit(buf, "%d\n", card->sanitize_timeout_ms);
> +}
> +
> +static ssize_t sanitize_timeout_ms_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t len)
> +{
> + struct mmc_card *card = mmc_dev_to_card(dev);
> + unsigned int new;
> + int ret;
> +
> + ret = kstrtouint(buf, 0, &new);
> + if (ret < 0)
> + return ret;
> +
> + if (new == 0)
> + return -EINVAL;
> +
> + card->sanitize_timeout_ms = new;
> +
> + return len;
> +}
> +static DEVICE_ATTR_RW(sanitize_timeout_ms);
> +
> +
> static struct attribute *mmc_std_attrs[] = {
> &dev_attr_cid.attr,
> &dev_attr_csd.attr,
> @@ -861,6 +893,7 @@ static struct attribute *mmc_std_attrs[] = {
> &dev_attr_rca.attr,
> &dev_attr_dsr.attr,
> &dev_attr_cmdq_en.attr,
> + &dev_attr_sanitize_timeout_ms.attr,
> NULL,
> };
> ATTRIBUTE_GROUPS(mmc_std);
> @@ -1623,6 +1656,7 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
> card->ocr = ocr;
> card->type = MMC_TYPE_MMC;
> card->rca = 1;
> + card->sanitize_timeout_ms = MMC_SANITIZE_TIMEOUT_MS;
> memcpy(card->raw_cid, cid, sizeof(card->raw_cid));
> }
>
> diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
> index f413474f0f80..40a4f9e22d30 100644
> --- a/drivers/mmc/core/mmc_ops.c
> +++ b/drivers/mmc/core/mmc_ops.c
> @@ -21,7 +21,6 @@
>
> #define MMC_BKOPS_TIMEOUT_MS (120 * 1000) /* 120s */
> #define MMC_CACHE_FLUSH_TIMEOUT_MS (30 * 1000) /* 30s */
> -#define MMC_SANITIZE_TIMEOUT_MS (240 * 1000) /* 240s */
>
> static const u8 tuning_blk_pattern_4bit[] = {
> 0xff, 0x0f, 0xff, 0x00, 0xff, 0xcc, 0xc3, 0xcc,
> @@ -1025,7 +1024,7 @@ int mmc_sanitize(struct mmc_card *card)
> mmc_retune_hold(host);
>
> err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_SANITIZE_START,
> - 1, MMC_SANITIZE_TIMEOUT_MS);
> + 1, card->sanitize_timeout_ms);
> if (err)
> pr_err("%s: Sanitize failed err=%d\n", mmc_hostname(host), err);
>
> diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
> index f9ad35dd6012..9db0dcd9661e 100644
> --- a/include/linux/mmc/card.h
> +++ b/include/linux/mmc/card.h
> @@ -273,6 +273,7 @@ struct mmc_card {
>
> bool reenable_cmdq; /* Re-enable Command Queue */
>
> + unsigned int sanitize_timeout_ms;
> unsigned int erase_size; /* erase size in sectors */
> unsigned int erase_shift; /* if erase unit is power 2 */
> unsigned int pref_erase; /* in sectors */
> --
> 2.25.1
>
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