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 <[email protected]> > --- > 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 <[email protected]> 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 <[email protected]> --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
