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takezo

No USB Power (ROCK64+ARMBIAN 5.7)

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Armbianmonitor:

Hello, can someone help me with my problem.

I have a ROCK64 with 4GB of RAM and an ARMBIAN 5.75 stable Ubuntu 18.04.2 LTS 4.4.174-rockchip64, installed.
My issue come with usb ports, from the three USB of the this device only works two: one 2.0 and 3.0. And when i have a disk connected towards usb 3.0 i have issues with port usb 2.0, it doesn't work well and I end up disconnecting the USB 3.0 to can work with my device connected towards USB 2.0 so I assume that the current power on the USB port is having issues or it's not working well.

Anybody an idea?

 

thanks!

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So, let me ask some questions to make sure I have the full picture, and unpack some of this:

 

  1.  Have you tried booting the device with only 1 device plugged into the Rock64, in the usb2 port that is giving you trouble? 
  2. Is the USB3 drive you are using self-powered or powering from the USB port itself, and what are it's power requirements?

Some background:

 

One of the USB 2 ports on these boards is a USB OTG with the device tree specifying it as a host.  That used to be problematic before the "host" mode was explicitly stated.  That said, I don't think that's the issue here, although I'll double check a new image if I get time. 

 

The other issue is basic single board computer reality, which is always a tough pill to swallow:  The entire board only has available the amount of power a single USB 3.0 port is allowed to consume according to specification.  I wish USB had some kind of split specification compliance so that you could show that your device is USB3 communication compliant but not USB 3.0 power compliant.  It sounds like the USB power is falling below 4.75 volts and some of your devices are disconnecting due to under powering. 

 

If the drive has no provisions for power other than the USB port, then a powered hub or powering the board via GPIO (only for the experienced) is recommended.  Even if the drive seems to work without other things plugged in, you will face data corruption if you're underpowering it.

 

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