USB driver locking

Hans Petter Selasky hselasky at
Wed May 25 07:53:10 UTC 2011

On Wednesday 25 May 2011 09:47:50 Daniel O'Connor wrote:
> On 25/05/2011, at 9:33, Hans Petter Selasky wrote:
> > On Tuesday 24 May 2011 23:48:30 Daniel O'Connor wrote:
> >> I find that my application has rare problems where it does not get a
> >> reply from the micro to a control bus packet, or perhaps the micro
> >> doesn't receive it (I need to add a sequence number or similar to my
> >> protocol to try and detect it I think).
> > 
> > There was a data toggle issue fixed with the EHCI recently, which
> > triggers depending on hardware timing. Are you running the latest
> > 8-stable or 9-
> This one?


> I have that as I am running 219926
> > current. There is also a new utility called usbdump, which can be used to
> > figure out what is going on.
> I am running 9-current (in production for my sins..)
> usbdump is useful but consumes too much CPU at my data rate :(

You probably need an USB analyzer to figure out the real problem. Have you 
tried to start usbdump only once the problem happens?


More information about the freebsd-usb mailing list