Problems mounting USB drive via USB OTG port

Lestrad · 09-22-2020, 04:09 AM

Hello to all. I have a Wandboard Quad running Arch Linux ARM v. 5.8.7-1-ARCH. it serves as a mini-NAS and has one USB A port and one USB Mini AB OTG port. I have a Seagate Backup Plus USB hard drive connected to the USB A port and it works flawlessly.

I would like to connect a second USB drive to the USB OTG port and mount it at boot time. I have tried commenting out the USB drive in fstab and then rebooting and plugging in the same drive to the USB OTG port via a USB A female-to-USB Mini B cable. But the drive seems to be detected as a USB hub, or is not detected at all:

Code:

[alarm@alarm ~]$ [ 3029.018790] ci_hdrc ci_hdrc.0: EHCI Host Controller
[ 3029.023760] ci_hdrc ci_hdrc.0: new USB bus registered, assigned bus number 2
[ 3029.050691] ci_hdrc ci_hdrc.0: USB 2.0 started, EHCI 1.00
[ 3029.056308] usb usb2: New USB device found, idVendor=1d6b, idProduct=0002, bcdDevice= 5.08
[ 3029.064613] usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[ 3029.071870] usb usb2: Product: EHCI Host Controller
[ 3029.076778] usb usb2: Manufacturer: Linux 5.8.7-1-ARCH ehci_hcd
[ 3029.082725] usb usb2: SerialNumber: ci_hdrc.0
[ 3029.087729] hub 2-0:1.0: USB hub found
[ 3029.091659] hub 2-0:1.0: 1 port detected

lsusb -t shows only:

Code:

/:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=ci_hdrc/1p, 480M
/:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ci_hdrc/1p, 480M

What can I do so that the USB HDD is detected as a storage device at boot time and mounted? The g_mass_storage module is in my device tree but I don't know how to get it to load at boot time and recognize the drive.

Any help would be appreciated.

Regards,
Les

sgosnell · 09-22-2020, 09:51 AM

I think my solution would be to use a powered USB hub and run both drives from the USB-A port. I've dealt with USB-OTG only in PDAs and phones, where it was already set up. I don't know enough about the implementation to help, but I'll be interested in seeing how it works out.

Lestrad · 09-22-2020, 10:45 AM

Quote:

Originally Posted by sgosnell

I think my solution would be to use a powered USB hub and run both drives from the USB-A port. I've dealt with USB-OTG only in PDAs and phones, where it was already set up. I don't know enough about the implementation to help, but I'll be interested in seeing how it works out.

Thanks! That would be a solution. But I'd like to at least try running both USB drives just off the Wandboard and its power supply. I currently have a SATA 3.5" HDD on the board's SATA port, but it requires its own 12V power supply. I like the idea of a NAS running off one 5V power supply. Also I like a challenge and an opportunity to learn more about Linux.

I will keep you posted and post notes when and if i make progress (or run into dead ends ;-))