On 13/04/12 07:19, Chuanxiao Dong wrote:
> --qty when calculating erase timeout for trim/erase & secure trim/erase
> can prevent the erase range crossing qty+1 erase groups, which made
> the final timeout value is too large for the host.
>
> When operate SECURE_ERASE, driver needs the erase range is aligned with
> erase size, otherwise do nothing and return an error. That is to say
> it is not necessary for SECURE_ERASE to --qty since it will never cross
> an erase group.
>
> Signed-off-by: Chuanxiao Dong <chuanxiao.dong@xxxxxxxxx>
> ---
> drivers/mmc/core/core.c | 9 ++++++++-
> 1 files changed, 8 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index e541efb..b5a393a 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -1761,7 +1761,7 @@ static unsigned int mmc_do_calc_max_discard(struct mmc_card *card,
> if (!qty)
> return 0;
>
> - if (qty == 1)
> + if (qty == 1 && arg != MMC_SECURE_ERASE_ARG)
> return 1;
arg is never MMC_SECURE_ERASE_ARG
>
> /* Convert qty to sectors */
> @@ -1772,6 +1772,13 @@ static unsigned int mmc_do_calc_max_discard(struct mmc_card *card,
> else
> max_discard = --qty * card->erase_size;
>
> + /*
> + * since SECURE_ERASE is erase group aligned, otherwise
> + * it cannot be erased in secure purpose, needn't --qty
> + */
> + if (arg == MMC_SECURE_ERASE_ARG)
> + max_discard += card->erase_size;
> +
> return max_discard;
> }
>
What about:
From: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Date: Mon, 21 May 2012 13:32:42 +0300
Subject: [PATCH] mmc: core: fix max_discard calculation
The maximum discard calculation was unnecessarily pessimistic
in the case of erasing entire erase groups. In that case, the
quantity does not need to be decreased by 1 to allow for
misalignment because the erasure is always aligned to whole
erase groups.
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
drivers/mmc/core/core.c | 22 +++++++++++++++++-----
1 files changed, 17 insertions(+), 5 deletions(-)
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 0b6141d..36bfdce 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1742,7 +1742,7 @@ static unsigned int mmc_do_calc_max_discard(struct mmc_card *card,
{
struct mmc_host *host = card->host;
unsigned int max_discard, x, y, qty = 0, max_qty, timeout;
- unsigned int last_timeout = 0;
+ unsigned int last_timeout = 0, aligned_qty;
if (card->erase_shift)
max_qty = UINT_MAX >> card->erase_shift;
@@ -1769,16 +1769,28 @@ static unsigned int mmc_do_calc_max_discard(struct mmc_card *card,
if (!qty)
return 0;
- if (qty == 1)
- return 1;
+ if (arg & MMC_TRIM_ARGS) {
+ /*
+ * The requested number of sectors may not be aligned to an
+ * erase group, so we have to decrease the quantity by 1 (unless
+ * it is 1) e.g. trimming 2 sectors could cause 2 erase groups
+ * to be affected even though 2 sectors is less than the size of
+ * 1 erase group.
+ */
+ if (qty == 1)
+ return 1;
+ aligned_qty = qty - 1;
+ } else {
+ aligned_qty = qty;
+ }
/* Convert qty to sectors */
if (card->erase_shift)
- max_discard = --qty << card->erase_shift;
+ max_discard = aligned_qty << card->erase_shift;
else if (mmc_card_sd(card))
max_discard = qty;
else
- max_discard = --qty * card->erase_size;
+ max_discard = aligned_qty * card->erase_size;
return max_discard;
}
--
1.7.6.5
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