Arch Linux

dimo

Member

Registered: 2017-12-04

Posts: 8

After update usb ports stop working. Alternatives to reboot?

Hi everyone, sometimes after I update the system with pacman -Syu, the usb ports stop working. By now if I insert a pen drive and i run lsblk -l I can't see it. If I plug in the mouse it's recognized as you can see from the output below, but it doesn't work. Usually i have to reboot the system. Is there an alternative?
lsusb output:

Bus 001 Device 004: ID 0781:5581 SanDisk Corp. Ultra
Bus 001 Device 002: ID 8087:8000 Intel Corp. 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 002 Device 004: ID 0bda:0129 Realtek Semiconductor Corp. RTS5129 Card Reader Controller
Bus 002 Device 005: ID 13d3:3423 IMC Networks 
Bus 002 Device 002: ID 04f2:b483 Chicony Electronics Co., Ltd 
Bus 002 Device 013: ID 1d57:ad17 Xenta
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 20,715

Re: After update usb ports stop working. Alternatives to reboot?

The problem is that, after you update the kernel, the old kernel is still the one in memory that is running.   The update removes the kernel modules for the old (running) kernel and installs the modules for the new kernel that will load the next time you boot.

Your options:  Load the modules you are going to need *before* you update the kernel (insert the USB device, then update) -or- preserve the existing kernel modules.  One way of doing this might be to copy them someplace, updating the kernel, and moving them back.  Note that this is *NOT* the recommended (Arch) way of doing things and will cause files to exist of which Pacman is unaware.  But, the kernel is (in my opinion) a corner case. I would prefer that, when a new kernel is installed, it not replace the old kernel and modules, but would leave them in place.  Each kernel in the boot partition would have to have a unique name, and would require the bootloader be updated to use newer kernels.   I guess I learned this habit in my Gentoo days

There is another option that I have heard about, but have never researched.  There may be a way to replace a running kernel; or at least I heard it was a project somewhere.

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