Comment 40 for bug 363812

Thank you for your guidance. Below my observations:

1. Set to hidden, radio blocked or something like that in the BIOS setup screens (usually cannot be reenabled by software until reconfigured in BIOS);

>Disabled/re-enabled wireless in BIOS. No effect.

2. Disabled in software, and not re-enabled (warning: this state *IS* kept across reboots and power down). In this case, thinkpad-acpi is supposed to be able to re-enable the device, if you use the rfkill sysfs class to do it;

>thinkpad-acpi does not show rfkill for the wwan, only for wifi card.

3. Radio-kill physical switch is enabled (i.e. radios are killed). NOTHING can reenable the device until you disable the radio-kill switch. Mind you, I have been told there are kernel bugs in this area for some WLAN devices, but I haven't heard of any on the WWAN devices;

>Physical switch is ON. Wifi works, wwan used to work up to a few weeks ago.

4. The kernel rfkill subsystem orders thinkpad-acpi to kill the radio (check /sys/class/rfkill/*), which it can do at any time, for any reason;

>No rfkill for wwan card (used to be there)

5. Broken backports of the rfkill subsystem, or other kernel bugs.

>Possible

6. Make sure EHCI-HCD *and* UHCI-HCD are running properly, or the USB bus won't work, and obviously the device won't be there even if it is enabled.

> built-in kernel for 2.6.28-11, lspci -v shows that they are loaded and working.
>>>Are we dependent on these two being build as modules?
>This was the case in 2.6.27-11 and changed with the newer kernel.