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Date: Mon, 1 Aug 2016 15:28:14 +0800
From: Baolin Wang <baolin.wang@...aro.org>
To: Shawn Lin <shawn.lin@...k-chips.com>
Cc: Ulf Hansson <ulf.hansson@...aro.org>,
Adrian Hunter <adrian.hunter@...el.com>,
Russell King <rmk+kernel@....linux.org.uk>,
Douglas Anderson <dianders@...omium.org>,
Heiko Stübner <heiko@...ech.de>,
David Jander <david@...tonic.nl>,
Hans de Goede <hdegoede@...hat.com>,
linux-mmc <linux-mmc@...r.kernel.org>,
LKML <linux-kernel@...r.kernel.org>,
Mark Brown <broonie@...nel.org>,
Linus Walleij <linus.walleij@...aro.org>
Subject: Re: [PATCH v2] mmc: core: Optimize the mmc erase size alignment
Hi Ulf and Shawn,
On 27 July 2016 at 18:02, Baolin Wang <baolin.wang@...aro.org> wrote:
> On 27 July 2016 at 17:59, Shawn Lin <shawn.lin@...k-chips.com> wrote:
>> On 2016/7/27 15:17, Baolin Wang wrote:
>>>
>>> Before issuing mmc_erase() function, users always have checked if it can
>>> erase with mmc_can_erase/trim/discard() function, thus remove the
>>> redundant
>>> erase checking in mmc_erase() function.
>>>
>>> This patch also optimizes the erase start/end sector alignment with
>>> round_up()/round_down() function, when erase command is MMC_ERASE_ARG.
>>>
>>> Signed-off-by: Baolin Wang <baolin.wang@...aro.org>
>>> ---
>>> Changes since v1:
>>> - Add the alignment if card->erase_size is not power of 2.
>>> ---
>>> drivers/mmc/core/core.c | 78
>>> +++++++++++++++++++++++++++++------------------
>>> 1 file changed, 48 insertions(+), 30 deletions(-)
>>>
>>> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
>>> index b4c08d1a..303a917 100644
>>> --- a/drivers/mmc/core/core.c
>>> +++ b/drivers/mmc/core/core.c
>>> @@ -2195,6 +2195,51 @@ out:
>>> return err;
>>> }
>>>
>>> +static unsigned int mmc_align_erase_size(struct mmc_card *card,
>>> + unsigned int *from,
>>> + unsigned int *to,
>>> + unsigned int nr)
>>> +{
>>> + unsigned int from_new = *from, nr_new = nr, rem;
>>> +
>>> + if (is_power_of_2(card->erase_size)) {
>>> + unsigned int temp = from_new;
>>> +
>>> + from_new = round_up(temp, card->erase_size);
>>> + rem = from_new - temp;
>>> +
>>> + if (nr_new > rem)
>>> + nr_new -= rem;
>>> + else
>>> + return 0;
>>> +
>>> + nr_new = round_down(nr_new, card->erase_size);
>>> + } else {
>>> + rem = from_new % card->erase_size;
>>> + if (rem) {
>>> + rem = card->erase_size - rem;
>>> + from_new += rem;
>>> + if (nr_new > rem)
>>> + nr_new -= rem;
>>> + else
>>> + return 0;
>>> + }
>>> +
>>> + rem = nr_new % card->erase_size;
>>> + if (rem)
>>> + nr_new -= rem;
>>> + }
>>> +
>>> + if (nr_new == 0)
>>> + return 0;
>>> +
>>> + /* 'from' and 'to' are inclusive */
>>> + *to = from_new + nr_new - 1;
>>> + *from = from_new;
>>> +
>>> + return nr_new;
>>> +}
>>> +
>>> /**
>>> * mmc_erase - erase sectors.
>>> * @card: card to erase
>>> @@ -2210,13 +2255,6 @@ int mmc_erase(struct mmc_card *card, unsigned int
>>> from, unsigned int nr,
>>> unsigned int rem, to = from + nr;
>>> int err;
>>>
>>> - if (!(card->host->caps & MMC_CAP_ERASE) ||
>>> - !(card->csd.cmdclass & CCC_ERASE))
>>
>>
>> Why remove the check , "!(card->csd.cmdclass & CCC_ERASE))"?
>
> Cause we always issue mmc_can_erase() function before strating to do
> mmc erase, so these looks like redundant.
Do you have any other comments about this patch? Thanks.
>
>>> - return -EOPNOTSUPP;
>>> -
>>> - if (!card->erase_size)
>>> - return -EOPNOTSUPP;
>>> -
>>> if (mmc_card_sd(card) && arg != MMC_ERASE_ARG)
>>> return -EOPNOTSUPP;
>>>
>>> @@ -2234,31 +2272,11 @@ int mmc_erase(struct mmc_card *card, unsigned int
>>> from, unsigned int nr,
>>> }
>>>
>>> if (arg == MMC_ERASE_ARG) {
>>> - rem = from % card->erase_size;
>>> - if (rem) {
>>> - rem = card->erase_size - rem;
>>> - from += rem;
>>> - if (nr > rem)
>>> - nr -= rem;
>>> - else
>>> - return 0;
>>> - }
>>> - rem = nr % card->erase_size;
>>> - if (rem)
>>> - nr -= rem;
>>> + rem = mmc_align_erase_size(card, &from, &to, nr);
>>> + if (rem == 0)
>>> + return 0;
>>> }
>>>
>>> - if (nr == 0)
>>> - return 0;
>>> -
>>> - to = from + nr;
>>> -
>>> - if (to <= from)
>>> - return -EINVAL;
>>> -
>>> - /* 'from' and 'to' are inclusive */
>>> - to -= 1;
>>> -
>>> /*
>>> * Special case where only one erase-group fits in the timeout
>>> budget:
>>> * If the region crosses an erase-group boundary on this
>>> particular
>>>
>>
>>
>> --
>> Best Regards
>> Shawn Lin
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
>> the body of a message to majordomo@...r.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
>
>
> --
> Baolin.wang
> Best Regards
--
Baolin.wang
Best Regards
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