Subject: Re: WANT PMAPLOAD ON SYSCALL ENTRY warnings
To: None <M.Drochner@fz-juelich.de>
From: Lennart Augustsson <firstname.lastname@example.org>
Date: 04/28/2005 17:28:34
usbd_do_request() has to be used very carefully from
a non-process context. Perhaps you should consider a
Matthias Drochner wrote:
> Hi -
> I'm currently experimenting with some poor USB device
> which receives the DCF77 timing signal. Final goal
> is to get this fed into ntpd.
> That device is completely misdesiged but relatively cheap --
> one has to poll it through USB control transfers to get the
> slopes of the timing signal. One can't expect an accuracy
> better than 10ms (HZ) that way, but that would be enough for
> our application (remote data loggers).
> Anyway, what my driver does is to issue these control
> requests (usbd_do_request()) within a callout(9)
> handler, and to stuff the result into a tty.
> Now I'm getting a kernel diagnostic warning from tome to time:
> WARNING: WANT PMAPLOAD ON SYSCALL ENTRY
> Am I doing something illegal?
> best regards