svn commit: r198431 - head/sys/dev/pci

John Baldwin jhb at
Mon Oct 26 15:45:18 UTC 2009

On Friday 23 October 2009 6:53:01 pm Marcel Moolenaar wrote:
> Author: marcel
> Date: Fri Oct 23 22:53:01 2009
> New Revision: 198431
> URL:
> Log:
>   BIOSes, buggy or otherwise, are i386 or amd64 specific.
>   Have the early USB takeover enabled for i386 and amd64
>   by default.
>   This also avoids a panic on PowerPC where the resource
>   isn't released properly and we find a busy resource
>   when the USB host controller wants to allocate it...

Presumably such systems won't set the 'BIOS owned' bit in the their legacy 
support registers in which case these routines are NOPs (they just read the 
register, see the bit is clear, and exit).  The resource bug sounds like a 
real one that should be fixed and would probably affect any x86 systems who 
have USB disabled in the BIOS, so that should be fixed rather than papered 
over.  Please revert.

Note that the legacy support register stuff is part of the uhci/ohci/ehci 
specifications, and that the code to frob it has been part of the same 
drivers since their inception.  If it had been an actual problem then it 
would have been disabled back when USB was enabled for other architectures.

John Baldwin

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