imx8qxp - eMMC pseudoSLC

[sergey_tarassen]

Hello,

we are trying to activate pseudoSLC mode on eMMC on custom imx8qxp board. We have tried with different eMMC chips, one from Micron ( MTFC8GAMALBH-IT ) and another from ISSI, both can MMC 5.x Standard so it should be supported.

from uboot before partitioning
=> mmc info
Device: FSL_SDHC
Manufacturer ID: 9d
OEM: 101
Name: IS008
Bus Speed: 200000000
Mode : HS200 (200MHz)
Rd Block Len: 512
MMC version 5.0
High Capacity: Yes
Capacity: 7.3 GiB
Bus Width: 8-bit
Erase Group Size: 512 KiB
HC WP Group Size: 8 MiB
User Capacity: 7.3 GiB WRREL
Boot Capacity: 4 MiB ENH
RPMB Capacity: 4 MiB ENH

=> mmc hwpartition user enh 0 7634944 wrrel on check
Partition configuration:
User Enhanced Start: 0 Bytes
User Enhanced Size: 3.6 GiB
User partition write reliability: on
No GP1 partition
No GP2 partition
No GP3 partition
No GP4 partition

=> mmc hwpartition user enh 0 7634944 wrrel on complete
Partition configuration:
User Enhanced Start: 0 Bytes
User Enhanced Size: 3.6 GiB
User partition write reliability: on
No GP1 partition
No GP2 partition
No GP3 partition
No GP4 partition
Partitioning successful, power-cycle to make effective

after power-cycle (it was only reboot)

=> mmc info
Device: FSL_SDHC
Manufacturer ID: 9d
OEM: 101
Name: IS008
Bus Speed: 200000000
Mode : HS200 (200MHz)
Rd Block Len: 512
MMC version 5.0
High Capacity: Yes
Capacity: 7.3 GiB
Bus Width: 8-bit
Erase Group Size: 512 KiB
HC WP Group Size: 8 MiB
User Capacity: 7.3 GiB ENH WRREL
User Enhanced Start: 0 Bytes
User Enhanced Size: 3.6 GiB
Boot Capacity: 4 MiB ENH
RPMB Capacity: 4 MiB ENH

=> mmc hwpartition
Partition configuration:
        No enhanced user data area
        No GP1 partition
        No GP2 partition
        No GP3 partition
        No GP4 partition
Card already partitioned
Failed!

For some reason enhanced area is configured but not present???, also capacity and user capacity are still reported as 7.3GiB instead of 3.6 GiB

I've attached complete output of mmc extcsd read /dev/mmcblk0 after partitioning. Data looks correct for me:

Partitioning is supported:

Partitioning Support [PARTITIONING_SUPPORT]: 0x07
Device support partitioning feature
Device can have enhanced tech.

Partitioning was done:

Partitioning Setting [PARTITION_SETTING_COMPLETED]: 0x01
Device partition setting complete

Enhanced (pSLC) Area 3.6GiB starts at 0:

Enhanced User Data Area Size [ENH_SIZE_MULT]: 0x0001d2
i.e. 3817472 KiB
Enhanced User Data Start Address [ENH_START_ADDR]: 0x00000000
i.e. 0 bytes offset

Any Idea what could be wrong here? I've used steps from this manual ( https://www.embeddedartists.com/wp-content/uploads/2020/04/Working_with_eMMC.pdf ) and tried both u-boot (described here) and linux procedure (with another chip, since partitioning can be done only once)

Thank you in advance!

[laodzu]

Hi Sergey, indeed the output of mmc extcsd read seems to contradict what U-Boot reports.  Can you show us what Linux thinks of the partitions on /dev/mmcblk0 now? I.e. the output of fdisk -l /dev/mmcblk0.

Thanks in advance!

[sergey_tarassen · Accepted solution]

~# fdisk -l /dev/mmcblk0

Disk /dev/mmcblk0: 3.66 GiB, 3909091328 bytes, 7634944 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

=> mmc info
Device: FSL_SDHC
Manufacturer ID: 9d
OEM: 101
Name: IS008
Bus Speed: 200000000
Mode : HS200 (200MHz)
Rd Block Len: 512
MMC version 5.0
High Capacity: Yes
Capacity: 3.6 GiB
Bus Width: 8-bit
Erase Group Size: 512 KiB
HC WP Group Size: 8 MiB
User Capacity: 3.6 GiB ENH WRREL
User Enhanced Start: 0 Bytes
User Enhanced Size: 3.6 GiB
Boot Capacity: 4 MiB ENH
RPMB Capacity: 4 MiB ENH

Hm... Likely the problem was missing power cycle, now everything looks fine in both linux and in u-boot.

Home office is well, but sadly no remote for power supply

[laodzu]

Hi Sergey,

thanks for acknowledging that there is no problem.  Indeed, the power cycle is essential but as you mentioned that explicitly in the text, I did not question it.  So cool, that everything works!