I have an Arch-based server (Zotac Nano, AMD Kabini-based) which doubles as WiFi access point using a miniPCI Atheros WiFi card.
If I start it form cold boot (as in “it was off”), then everything starts and works fine 100% of the time. However, if I then run “reboot” command, then there is 80% chance that then the system is back online, the WiFi card will be gone.
Here is dmesg after cold boot: http://pastebin.com/raw/CGsy9iqX
and dmesg after reboot: http://pastebin.com/raw/61LMJXEG
The card is physically visible regardless, because lspci remains unchanged: http://pastebin.com/raw/8R2LLTWX
I had this problem since a year now. With every kernel update there was over this period. It is a remote server, so being able to manually turn it in after a shutdown is rarely possible.