Actually, Specfication is described to be misunderstood easily.

Nice day.

2012/3/29 Dong, Chuanxiao [off-list ref]:

quoted

-----Original Message-----
From: Namjae Jeon [mailto:linkinjeon@gmail.com]
Sent: Thursday, March 29, 2012 11:30 AM
To: Dong, Chuanxiao
Cc: linux-mmc@vger.kernel.org; cjb@laptop.org; Hunter, Adrian
Subject: Re: [Patch v1]mmc:core: correct mmc_erase_timeout calculation

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

Thanks Namjae, seems I misunderstand the meaning of "Erase Timeout". It just means a timeout value for erase operation.

quoted

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 [off-list ref]:

quoted

quoted

-----Original Message-----
From: Namjae Jeon [mailto:linkinjeon@gmail.com]
Sent: Wednesday, March 28, 2012 8:36 PM
To: Dong, Chuanxiao
Cc: linux-mmc@vger.kernel.org; cjb@laptop.org; 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.

quoted

Does someone else can correct me if my understanding about the erase timeout

calculation is wrong?

quoted

Thanks
Chuanxiao

quoted

Thanks.

2012/3/28 Dong, Chuanxiao [off-list ref]:

quoted

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

quoted

-----Original Message-----
From: Namjae Jeon [mailto:linkinjeon@gmail.com]
Sent: Wednesday, March 28, 2012 5:17 PM
To: Dong, Chuanxiao
Cc: linux-mmc@vger.kernel.org; cjb@laptop.org; 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 [off-list ref]:

quoted

According to JEDEC 7.8.2, mmc_erase_timeout calculation should be

follow:

quoted

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quoted

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1. Secure erase timeout = 300ms * ERASE_TIMEOUT_MULT *
SEC_ERASE_MULT 2. Secure trim timeout = 300ms *
ERASE_TIMEOUT_MULT *

SEC_TRIM_MULT 3.

quoted

quoted

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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 <redacted>
---
 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

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