Refresh USB port / restart usb service

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Refresh USB port / restart usb service

Hello,

after the upgrade to Catalina I have some problem with the USB hubs. I have three USB hubs (all working fine before the upgrade) that when plugged they are recognised once every 10/15 times. If I plug the usb hub and then restart my Macbook (12", USB C port only) they are working fine.

I can't keep logging out or restarting each time I need to connect one, and I have already tried to restore my Mac without using any backup (huge waste of time, really ). So I am looking for a way to kill/restart the USB service manually via terminal. The hubs are HDMI, Ethernet and USB hubs, each feature works fine without issue, just the USB doesn't work until restart.

There's no driver or anything to install as they always have been plug and play. I know that Catalina has removed any support to 32bit application but again, there's no software that was needed. It's not a matter of kext because as I said if I restart my Mac everything is working fine.

Anyone aware of how to kill restart the usb kext/process?

Thank you very much

Posted on Jan 25, 2020 4:30 AM

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Answer 1

Feb 13, 2020 5:54 PM in response to WorldsAdmin

WorldsAdmin wrote:

I need a way to do it without rebooting / logging out

SMC has been reset few times, MacBook (Retina, 12-inch, Early 2015), both the hubs are not self powered, before doing few test one of the hub seller sent a new, same problem. I tried with two different hubs. I only need a way in terminal to refresh the USB accessories attached

Did you try simply:

sudo nvram boot-args=”-p -r”

this will tell you if a reboot is required, if no change—then you can answer your own question.

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Answer 2

WorldsAdmin Author

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Feb 17, 2020 3:29 PM in response to leroydouglas

I am not sure what this command should do but when I try it in terminal I get this:

nvram: Error setting variable - 'boot-args': (iokit/common) not permitted

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Answer 3

WorldsAdmin Author

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Jan 25, 2020 11:26 AM in response to leroydouglas

I need a way to do it without rebooting / logging out. Sometimes I need to use USB ports without the time to close all the work and reboot

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Answer 4

WorldsAdmin Author

Level 1

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Feb 10, 2020 1:26 PM in response to WorldsAdmin

Does anyone have any suggestion? If I logout or reboot the device works fine

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Answer 5

WorldsAdmin Author

Level 1

8 points

Feb 13, 2020 11:33 AM in response to Old Toad

SMC has been reset few times, MacBook (Retina, 12-inch, Early 2015), both the hubs are not self powered, before doing few test one of the hub seller sent a new, same problem. I tried with two different hubs. I only need a way in terminal to refresh the USB accessories attached

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Answer 6

Jan 25, 2020 10:26 AM in response to WorldsAdmin

Both Rebooting and NVRAM re-set port definition.

alternatively from the command line, copy &paste:

sudo nvram boot-args=”-p -r” && reboot

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Answer 7

Old Toad

Level 10

208,373 points

Feb 10, 2020 2:14 PM in response to WorldsAdmin

Try resetting the SMC: How to reset the SMC of your Mac - Apple Support. You may have to do it a couple of times.

What model Mac do you have and are the hubs self powered?

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Answer 8

WorldsAdmin Author

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Jan 25, 2020 6:03 AM in response to WorldsAdmin

After three NVRAM reset it seems that the issue is solved

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Answer 9

WorldsAdmin Author

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Jan 25, 2020 10:12 AM in response to WorldsAdmin

Unfortunately the problem is still there. Anyone is aware of a command that can be useful?

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Refresh USB port / restart usb service

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