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On startup it hangs on "Waiting for UDev uevents to be processed". Sometimes an extra row saying "[ 6.423351] firewire_ohci: Failed to set Link Power Status" is shown, and sometimes the screen goes all black before it hang.
Last time I was logged in I made some upgrades (pacman -Syu), so I guess that could have caused this problem but I'm not sure how to fix it.
What should I do?
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This is most probably a kernel bug. More specifically, a problem in a module that is being loaded on boot by udev. You can boot into your system by appending "init=/bin/bash" to your kernel commandline (in GRUB). First of all I'd uninstall any third-party (unsupported) kernel modules that you might have installed. If that does not work I'd revert to a previous kernel version and file a bug.
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