USB swticher loses connection to USB ports - Dell XPS-15 (usbcore.autosuspend issue?)

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bvz
Posts: 18
Joined: 2017/09/14 07:27:51

USB swticher loses connection to USB ports - Dell XPS-15 (usbcore.autosuspend issue?)

Post by bvz » 2021/08/23 19:31:30

{EDIT: Sorry - I had to completely re-write this question due to some new info...}

I have a Dell XPS15 running through a cheap USB switcher. Whenever I switch away from the Dell it seems to lose the ability to connect to the devices on this switcher (keyboard, mouse, graphics tablet) when switching back. The mouse does not even appear to be powered on.

Continuously mashing the mouse buttons while plugging and uplugging the usb connection to the switcher resets the connection about 10% of the time. But mostly the keyboard and mouse are just dead. Plugging a new mouse into the same port works, but unplugging it and then plugging the switcher back in still refuses to work.

This link (https://unix.stackexchange.com/question ... 0-or-above) seems to suggest that it is the usbcore autosuspend feature that may be the culprit. But the solution provided apparently does not apply to CentOS7. I tried modifying my grub file to disable autosuspend as suggested, (by adding the string: usbbcore.autosuspend=-1 to the end of the GRUB_CMDLINE_LINUX line) but when I check:

Code: Select all

cat /sys/module/usbcore/parameters/autosuspend
I still get back "2".

Question #1:

Is there a way to change this value to be -1 for this current session? I tried this command:

Code: Select all

sudo echo -1 >/sys/module/usbcore/parameters/autosuspend
but get back a "Permission denied" error.

[EDIT: sudo apparently does not allow me to change this, but using the su command and becomming root does. At first glance, setting this to -1 seems to fix this issue, so it appears that I just need to figure out how to change it permanently.)


Question #2:

How do I change usbcore.autosuspend to be -1 across reboots?

Thanks!

bvz
Posts: 18
Joined: 2017/09/14 07:27:51

Re: USB swticher loses connection to USB ports - Dell XPS-15 (usbcore.autosuspend issue?)

Post by bvz » 2021/08/25 04:10:08

TrevorH solved my problem over in this thread:

viewtopic.php?f=47&t=78058&p=328026#p328026

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