"ums 0 mmc 0" doesn't work

[MEige]

Hello,

I can't use the "ums" command via terminalprog (minicom)

Message is always

"STM32MP> ums 0 mmc 0

UMS: LUN 0, dev 0, hwpart 0, sector 0x0, count 0x1dacc00

Please connect USB cable. "

After 60 seconds: "USB cable not detected. Command exit."

Communication via minicom/ST-Link and ETH works.

STM32MP> usb start

starting USB...

USB0:  USB EHCI 1.00

scanning bus 0 for devices... 2 USB Device(s) found

scanning usb for storage devices... 0 Storage Device(s) found

System is buildroot, an older one and a version with kernel 5.8. No difference.

I can't find the mistake.

Marc

[OlivierK]

Hello MEige (Community Member)

Do you use a custom board or an ST board? If you use an STM32MP157C-DK2 board, after "STM32MP> ums 0 mmc 0" just plug an USB OTG type C cable as mentioned to open an USB mass storage device in U-boot. What happens when you do so?

Regards,

Olivier

[MEige · Accepted solution]

Hello Olivier,

the missing and a wrong USB cable was the problem. One of the USB cables is for charging/power supply only. And that cable was connected to the OTG.

The datalines of such cables are not connected inside. This type of cable is cheaper to manufacture. It's a commone trap (Many Type B cables suffer from this problem also). The problem is solved.

Thank you for your help.

Marc