USB via module instead of kernel?

Jesse Sheidlower jester at
Mon Apr 12 19:34:17 PDT 2004

I'm new to this kernel-module thing, so I hope this isn't
a silly question.

I'm using FreeBSD 5.2 on a laptop running ACPI, and like
many others have had suspend/resume problems with the 
USB dying on resume. I saw a suggestion somewhere that
you could remove USB support from the kernel, and add it
in via a .ko file at boot time; this way, you could have
an rc.suspend and rc.resume that unloads/loads the USB
module appropriately and perhaps avoid the problems.

I'm not entirely sure how to do this. First, I note
that the "device usb" line in the kernel configuration
file has a "Required" note in it, and I'm nervous about
removing something that says "Required".

Second, while I have a usb.ko file under /boot/kernel/, if I
type "kldload usb", I get a "can't load usb: File exists"
message, but if I try "kldunload usb", I get "can't find file
usb: No such file or directory". I might have expected a
different message if usb is loaded as part of the kernel. If I
want to enable it at boot, do I just add "usb_load="YES"" to
/boot/loader.conf ?

So to summarize, I guess my questions are:

1) Can I comment out "device usb" from my kernel config and
then rebuild the kernel, without causing some big problem?

2) To load at boot, do I just add "usb_load="YES"" to
/boot/loader.conf ?

3) Will doing what I described help with the USB problems
on suspend/resume?

Thanks very much.

Jesse Sheidlower

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