Broadcom "wl" with "VT for Direct I/O" does not work

Sean Millichamp sean at
Tue Dec 8 09:30:50 CST 2009

I wanted to post a warning to anyone else who might want to try this
combination and need the support.

I posted about a week ago about issues I was having with the Broadcom wl
wireless driver and my laptop.  I finally isolated the problem.

Dell Latitude E5500 with Dell Wireless 1397 (aka Broadcom BCM4312)

OS: Fedora 12 64-bit,

In the BIOS there is an option to enable/disable the Intel hardware
virtualization support, there is also a suboption to enable/disable "VT
for Direct I/O".

If hardware virtualization support is enabled AND the "VT for Direct
I/O" support is also enabled then the wl driver seems unable to
function.  All of my other (open source driver) hardware seems to work
fine with it enabled, but wl fails to initialize properly and no
wireless networks are ever visible or usable.

Dec  8 08:38:32 sewt kernel: wl: module license 'unspecified' taints kernel.
Dec  8 08:38:32 sewt kernel: Disabling lock debugging due to kernel taint
Dec  8 08:38:32 sewt kernel: wl 0000:0c:00.0: PCI INT A -> GSI 17 (level, low) -> IRQ 17
Dec  8 08:38:34 sewt kernel: DRHD: handling fault status reg 2
Dec  8 08:38:34 sewt kernel: DMAR:[DMA Read] Request device [0c:00.0] fault addr fffeb000 
Dec  8 08:38:34 sewt kernel: DMAR:[fault reason 06] PTE Read access is not set

The last three lines only appear when "VT for Direct I/O" support is enabled.

wl driver version

I just notified Broadcom via their
linux-wlan-client-support-list at address.

For now I will run with "VT for Direct I/O" disabled as I need wireless
and KVM will work without that support enabled.

Hope that helps someone,

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