You should get results like this:
$ lsmod | grep blue
bluetooth 61028 4 rfcomm,l2cap
$ dmesg | grep Blue
[ 44.533912] Bluetooth: Core ver 2.11
[ 44.534296] Bluetooth: HCI device and connection manager initialized
[ 44.534301] Bluetooth: HCI socket layer initialized
[ 44.611716] Bluetooth: L2CAP ver 2.9
[ 44.611723] Bluetooth: L2CAP socket layer initialized
[ 44.673976] Bluetooth: RFCOMM socket layer initialized
[ 44.673994] Bluetooth: RFCOMM TTY layer initialized
[ 44.673998] Bluetooth: RFCOMM ver 1.8
$ hciconfig -a
When it just goes to the next input line and otherwise does nothing, then you do not have the required bit installed. Note that in the example above, the command hciconfig -a does nothing? That is because I have no bluetooth devices or HW. My distro includes the driver as a convenience only.
If the lsmod line (the first one in the example) does this, then the module is not installed.
The dmesg commands should not hang - they should return some lines or just provide a new input prompt. Since you do not have the module, you won't get any dmesg record concerning it.
Review the linux journal article from my last post.
You probably have to install the bluetooth tools package for your distribution
Here is a mandriva wiki page about enabling bluetooth - it looks out of date but I have not kept up with mandriva either:
mandriva 2008.1 had a "bluetooth dialup networking" tool in Mandriva control panel > Setup a new network interface. There is also a blog discussion about bluetooth+phones in mandriva here: