Re: [Patch v1]mmc:core: correct mmc_erase_timeout calculation

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I think that write block delay * SECURE_ERASE_MULT is right in case of
secure erase + ERASE_GROUP_DEF disable.

See the specification contents on 4.4.1.
Erase / Secure Erase
The duration of an erase command will be (order of magnitude) the
number of Erase blocks to be erased
multiplied by the block write delay. If ERASE_GROUP_DEF (EXT_CSD byte
[175]) is enabled,
ERASE_TIMEOUT_MULT should be used to calculate the duration.
Secure Erase timeout is calculated based on the Erase Timeout and
additional SEC_ERASE_MULT factor
(EXT_CSD byte [230]).

Thanks.

2012/3/29 Dong, Chuanxiao <chuanxiao.dong@xxxxxxxxx>:
>> -----Original Message-----
>> From: Namjae Jeon [mailto:linkinjeon@xxxxxxxxx]
>> Sent: Wednesday, March 28, 2012 8:36 PM
>> To: Dong, Chuanxiao
>> Cc: linux-mmc@xxxxxxxxxxxxxxx; cjb@xxxxxxxxxx; Hunter, Adrian
>> Subject: Re: [Patch v1]mmc:core: correct mmc_erase_timeout calculation
>>
>> If ERASE_GROUP_DEF is disable with secure erase, erase timeout is calculated with
>> 300ms * ERASE_TIMEOUT_MULT. Is it right ?
>
> My understanding about the JESD84-A441 is different with current mmc_mmc_erase_timeout implemented. From the EXT_CSD[230], seems no matter ERASE_GROUP_DEF is enabled or not, secure erase timeout is calculated as 300ms * ERASE_TIMEOUT_MULT * SECURE_ERASE_MULT. That is why I submitted this patch.
>
> Does someone else can correct me if my understanding about the erase timeout calculation is wrong?
>
> Thanks
> Chuanxiao
>
>>
>> Thanks.
>>
>> 2012/3/28 Dong, Chuanxiao <chuanxiao.dong@xxxxxxxxx>:
>> > What I am checking with is eMMC4.41 spec, not eMMC4.5 spec.
>> > Forward you the link:
>> > www.jedec.org/sites/default/files/docs/JESD84-A441.pdf
>> >
>> > Thanks
>> > Chuanxiao
>> >
>> >> -----Original Message-----
>> >> From: Namjae Jeon [mailto:linkinjeon@xxxxxxxxx]
>> >> Sent: Wednesday, March 28, 2012 5:17 PM
>> >> To: Dong, Chuanxiao
>> >> Cc: linux-mmc@xxxxxxxxxxxxxxx; cjb@xxxxxxxxxx; Hunter, Adrian
>> >> Subject: Re: [Patch v1]mmc:core: correct mmc_erase_timeout
>> >> calculation
>> >>
>> >> Hi. Chuanxiao.
>> >> Would you share your specification with me ?
>> >> When I check the latest emmc 4.5 spec, I can not find it.
>> >> Thanks.
>> >>
>> >> 2012/3/28 Chuanxiao Dong <chuanxiao.dong@xxxxxxxxx>:
>> >> > According to JEDEC 7.8.2, mmc_erase_timeout calculation should be follow:
>> >> > 1. Secure erase timeout = 300ms * ERASE_TIMEOUT_MULT *
>> >> > SEC_ERASE_MULT 2. Secure trim timeout = 300ms * ERASE_TIMEOUT_MULT *
>> SEC_TRIM_MULT 3.
>> >> > Trim timeout = 300ms * TRIM_MULT 4. Erase timeout:
>> >> >   a. if ERASE_GROUP_DEF is true: Erase timeout = 300ms *
>> >> > ERASE_TIMEOUT_MULT
>> >> >   b. if ERASE_GROUP_DEF is false: Erase timeout = write block delay
>> >> >
>> >> > Signed-off-by: Chuanxiao Dong <chuanxiao.dong@xxxxxxxxx>
>> >> > ---
>> >> >  drivers/mmc/core/core.c |   42
>> >> > +++++++++++++++++++++++++++++-------------
>> >> >  1 files changed, 29 insertions(+), 13 deletions(-)
>> >> >
>> >> > diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
>> >> > index 14f262e..d9d6d1c 100644
>> >> > --- a/drivers/mmc/core/core.c
>> >> > +++ b/drivers/mmc/core/core.c
>> >> > @@ -1405,12 +1405,36 @@ static unsigned int
>> >> > mmc_mmc_erase_timeout(struct mmc_card *card,
>> >> >  {
>> >> >        unsigned int erase_timeout;
>> >> >
>> >> > -       if (card->ext_csd.erase_group_def & 1) {
>> >> > -               /* High Capacity Erase Group Size uses HC timeouts
>> >> > */
>> >> > -               if (arg == MMC_TRIM_ARG)
>> >> > -                       erase_timeout = card->ext_csd.trim_timeout;
>> >> > +       /*
>> >> > +        * JEDEC 7.8.2
>> >> > +        *
>> >> > +        * 1. Secure erase/trim timeout is calculated absed on
>> >> > + Erase Timeout
>> >> > +        * and additional SEC_ERASE_MULT/SEC_TRIM_MULT.
>> >> > +        * So secure erase/trim timeout = ERASE Timeout *
>> >> > + SEC_ERASE_MULT/
>> >> > +        * SEC_TRIM_MULT.
>> >> > +        * ERASE Timeout = 300ms * ERASE_TIMEOUT_MULT
>> >> > +        *
>> >> > +        * 2. trim timeout is calculated based on the TRIM_MULT factor.
>> >> > +        * So trim timeout = 300ms * TRIM_MULT
>> >> > +        *
>> >> > +        * 3. erase timeout calculation:
>> >> > +        *      a. if ERASE_GROUP_DEF is enabled,
>> >> > + ERASE_TIMEOUT_MULT should be
>> >> > +        *      used to calculate erase timeout, so:
>> >> > +        *      erase timeout = 300 * ERASE_TIMEOUT_MULT
>> >> > +        *      b. if ERASE_GROUP_DEF is diabled, the duration of
>> >> > + an erase
>> >> > +        *      command will be the number of Erase blocks to be
>> >> > + erased
>> >> > +        *      multiplied by the block write delay.
>> >> > +        */
>> >> > +       if (arg & MMC_SECURE_ARGS) {
>> >> > +               erase_timeout = card->ext_csd.hc_erase_timeout;
>> >> > +               if (arg == MMC_SECURE_ERASE_ARG)
>> >> > +                       erase_timeout *=
>> >> > + card->ext_csd.sec_erase_mult;
>> >> >                else
>> >> > -                       erase_timeout =
>> >> > card->ext_csd.hc_erase_timeout;
>> >> > +                       erase_timeout *=
>> >> > + card->ext_csd.sec_trim_mult;
>> >> > +       } else if (arg & MMC_TRIM_ARGS) {
>> >> > +               erase_timeout = card->ext_csd.trim_timeout;
>> >> > +       } else if (card->ext_csd.erase_group_def & 1) {
>> >> > +               erase_timeout = card->ext_csd.hc_erase_timeout;
>> >> >        } else {
>> >> >                /* CSD Erase Group Size uses write timeout */
>> >> >                unsigned int mult = (10 << card->csd.r2w_factor); @@
>> >> > -1441,14 +1465,6 @@ static unsigned int
>> >> > mmc_mmc_erase_timeout(struct mmc_card *card,
>> >> >                        erase_timeout = 1;
>> >> >        }
>> >> >
>> >> > -       /* Multiplier for secure operations */
>> >> > -       if (arg & MMC_SECURE_ARGS) {
>> >> > -               if (arg == MMC_SECURE_ERASE_ARG)
>> >> > -                       erase_timeout *=
>> >> > card->ext_csd.sec_erase_mult;
>> >> > -               else
>> >> > -                       erase_timeout *=
>> >> > card->ext_csd.sec_trim_mult;
>> >> > -       }
>> >> > -
>> >> >        erase_timeout *= qty;
>> >> >
>> >> >        /*
>> >> > --
>> >> > 1.7.1
>> >> >
>> >> > --
>> >> > To unsubscribe from this list: send the line "unsubscribe linux-mmc"
>> >> > in the body of a message to majordomo@xxxxxxxxxxxxxxx More
>> >> > majordomo info at  http://vger.kernel.org/majordomo-info.html
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