mmc: stm32_sdmmc2: Increase SDMMC_BUSYD0END_TIMEOUT_US
Increase SDMMC_BUSYD0END_TIMEOUT_US from 1s to 2s to
avoid timeout error during blocks erase on some sdcard
Issue seen on Kingston 16GB :
Device: STM32 SDMMC2
Manufacturer ID: 27
OEM: 5048
Name: SD16G
Bus Speed: 50000000
Mode: SD High Speed (50MHz)
card capabilities: widths [4, 1] modes [SD Legacy, SD High Speed (50MHz)]
host capabilities: widths [4, 1] modes [MMC legacy, SD Legacy, MMC High Speed (26MHz), SD High Speed (50MHz), MMC High Speed (52MHz)]
Rd Block Len: 512
SD version 3.0
High Capacity: Yes
Capacity: 14.5 GiB
Bus Width: 4-bit
Erase Group Size: 512 Bytes
Issue reproduced with following command:
STM32MP> mmc erase 0 100000
MMC erase: dev # 0, block # 0, count 1048576 ... mmc erase failed
16384 blocks erased: ERROR
By setting SDMMC_BUSYD0END_TIMEOUT_US at 2 seconds and by adding
time measurement in stm32_sdmmc2_end_cmd() as shown below:
+start = get_timer(0);
/* Polling status register */
ret = readl_poll_timeout(priv->base + SDMMC_STA,
status, status & mask,
SDMMC_BUSYD0END_TIMEOUT_US);
+printf("time = %ld ms\n", get_timer(start));
We get the following trace:
STM32MP> mmc erase 0 100000
MMC erase: dev # 0, block # 0, count 1048576 ...
time = 17 ms
time = 1 ms
time = 1025 ms
time = 54 ms
time = 56 ms
time = 1021 ms
time = 57 ms
time = 56 ms
time = 1020 ms
time = 53 ms
time = 57 ms
time = 1021 ms
time = 53 ms
time = 57 ms
time = 1313 ms
time = 54 ms
time = 56 ms
time = 1026 ms
time = 54 ms
time = 56 ms
time = 1036 ms
time = 54 ms
time = 56 ms
time = 1028 ms
time = 53 ms
time = 56 ms
time = 1027 ms
time = 54 ms
time = 56 ms
time = 1024 ms
time = 54 ms
time = 56 ms
time = 1020 ms
time = 54 ms
time = 57 ms
time = 1023 ms
time = 54 ms
time = 56 ms
time = 1033 ms
time = 53 ms
time = 57 ms
....
time = 53 ms
time = 57 ms
time = 1021 ms
time = 56 ms
time = 56 ms
time = 1026 ms
time = 54 ms
time = 56 ms
1048576 blocks erased: OK
We see that 1 second timeout is not enough, we also see one measurement
up to 1313 ms. Set the timeout to 2 second to keep a security margin.
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
1 file changed