I have the same problem with Dell Latitude E7440, Ubuntu 20.04, after an update to kernel 5.4.0-92, and having linux-firmware 1.187.24.
1) I'm using a UGreen USB Switch to switch between the inputs of keyboard, mouse and audio between two stations 2) After the kernel and linux-firmware upgrade I did a reboot, the system took much longer to start (console shown "failed to enumerate USB devices"), when it did boot external keyboards and mouse wasn't working 3) Pluging in any device directly to laptop's USB port does not work 4) I've managed to get the external keyboard and mouse to work by disabling the Bluetooth in Ubuntu settings and rebooting back to 5.4.0-91 (worked via USB Switch) 5) However after another reboot to 5.4.0-91, USB ports stopped working again -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1956518 Title: linux-firmware 1.187.24 may crash USB ports To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-firmware/+bug/1956518/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs