USB Hub Support using iMX7 Dual Sabre Board

[christsang]

Hi everyone,

I am using the imx7d sabre board for development. I trying to have multiple usb mass storage devices mounted to the system via a usb hub. But debug messages give read error and there is no sdx device shown using the lsblk command.

The mass storage devices can be mounted well to the system by direction i.e. without usb hub. The USB hub is FE2.1 USB 2.0 HIGH SPEED 7-PORT HUB CONTROLLER. And I am using the Buildroot 2018.02 for my development.

Any advice? Thanks.

Chris Tsang

[christsang · Accepted solution]

Hi everyone, I have found the root cause for this problem. I just add dc power to the usb hub and it works properly on the imx7 sabre board now.

[Bio_TICFSL]

Hi Chris,

Check if this issue is not due to PMIC, I saw before but for i.mx6q:

ARM: imx6qdl-sabresd: set swbst_reg as vbus's parent reg      USB vbus 5V is from PMIC SWBST, so set swbst_reg as vbus's     parent reg, it fixed a bug that the voltage of vbus is incorrect     due to swbst_reg is disabled after boots up.

[christsang]

Hi Bio, so you mean that may be a hardware issue due to the incorrect voltage at the vbus? Or you mean swbst_reg should be set to other voltage?

[christsang]

Here is the log:

root@imx7dsabresd:~# random: nonblocking pool is initialized
usb 1-1: new high-speed USB device number 7 using ci_hdrc
usb 1-1: device not accepting address 7, error -71
usb 1-1: new high-speed USB device number 9 using ci_hdrc
hub 1-1:1.0: USB hub found
hub 1-1:1.0: 7 ports detected
usb 1-1: USB disconnect, device number 9
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: Cannot enable. Maybe the USB cable is bad?
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: Cannot enable. Maybe the USB cable is bad?
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: Cannot enable. Maybe the USB cable is bad?
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: cannot reset (err = -32)
usb usb1-port1: Cannot enable. Maybe the USB cable is bad?
usb usb1-port1: unable to enumerate USB device