sdmmc_host_t max_freq_khz limitation breaks SD card compatibility (IDFGH-14477)

[KenVanHoeylandt]

Answers checklist.

• I have read the documentation ESP-IDF Programming Guide and the issue is not addressed there.
• I have updated my IDF branch (master or release) to the latest version and checked that the issue is present there.
• I have searched the issue tracker for a similar issue and not found a similar issue.

IDF version.

5.3.2 and earlier

Espressif SoC revision.

ESP32, ESP32-S3

Operating System used.

Linux

How did you build your project?

Command line with CMake

If you are using Windows, please specify command line type.

None

Development Kit.

LilyGo T-Deck, M5Stack Core2, CYD 2432S024C, unPhone

Power Supply used.

USB

What is the expected behavior?

When setting the sdmmc_host_t::max_freq_khz to a value that is higher than allowed, the firmware automatically limits the frequency to 20 MHz as expected. This is reported in the idf.py monitor output.

However, as a side-effect, SD card compatibility is broken for most SD cards. I tried various SDHC cards from various brands and sizes (all SDHC) and only could get 1 card working.

When setting max_freq_khz to 20000 then all devices work fine and all SD cards are detected as normal.

 sdmmc_host_t host = SDSPI_HOST_DEFAULT();
 host.max_freq_khz = config->spiFrequencyKhz; // uint32_t with the value 800000
 host.slot = config->spiHost;

What is the actual behavior?

There should not be a side-effect that breaks compatibility, as all the cards work fine when setting 20 MHz manually.

Steps to reproduce.

1. Create host config: sdmmc_host_t host = SDSPI_HOST_DEFAULT();
2. Override frequency with unusually high value host.max_freq_khz = 800000; // 800 MHz!
3. Boot firmware and observe in monitor log that the frequency input was limited to 20 MHz
4. Observe how many/most SD cards don't mount anymore.
5. Change frequency manually to host.max_freq_khz = 20000; // 20 MHz
6. Observe how previously problematic SD cards now work fine

Debug Logs.

More Information.

I have not updated to ESP-IDF 5.4 yet, but I expect to do that in the coming month.

[adokitkat]

Hello. Could you please provide a log from idf.py monitor with log level set to debug and your sdkconfig file here please?

[KenVanHoeylandt]

I've attached everything you asked, but here's a summary:

With host.max_freq_khz = 800000; and that 1 SD card that I got working:

Name: SD32G
Type: SDHC/SDXC
Speed: 20.00 MHz (limit: 20.00 MHz)
Size: 30436MB
CSD: ver=2, sector_size=512, capacity=62333952 read_bl_len=9
SSR: bus_width=1

With host.max_freq_khz = 800000; and rare compatible SD card:

E (1336) sdmmc_sd: sdmmc_enable_hs_mode_and_check: send_csd returned 0x108
E (1336) vfs_fat_sdmmc: sdmmc_card_init failed (0x108).
HINT: Please verify if there is an SD card inserted into the SD slot. Then, try rebooting the board.
I (1338) gpio: GPIO[39]| InputEn: 1| OutputEn: 0| OpenDrain: 0| Pullup: 0| Pulldown: 0| Intr:0 
E (1348) spi_sdcard: Mounting failed (ESP_ERR_INVALID_RESPONSE)
E (1354) spi_sdcard: Mount failed for /sdcard
W (1359) hal: SD card mount failed (init can continue)

The monitor.txt attached is also with host.max_freq_khz = 800000 and with one of the many problematic SD cards.

monitor.txt
sdkconfig.board.lilygo-tdeck.txt
sdkconfig.txt