usbdrain problem (was: Re: "legacy" usb stack fixes)

[Hans Petter Selasky]

On Thursday 11 September 2008, Volker wrote:
> On 09/11/08 22:13, Julian Elischer wrote:
> > Volker wrote:
> >> On 09/11/08 10:13, Hans Petter Selasky wrote:
> >>> On Monday 25 August 2008, Volker wrote:
> >>>> Anyway, I've already had those crashes even with the "new" usb stack
> >>>> (but it doesn't happen everytime - YMMV).
> >>>

> >>
> >> // dropped current@ from CC
> >>
> >> Hans Petter,
> >>
> >> the device unplug problem is not just with usb, but these devices are
> >> the most frequent unplugged devices so far.
> >>
> >> Early this week, I discovered a new problem. I've fetched fresh RELENG_7
> >> sources, patched your usb stack in and recompiled kernel (using usb, not
> >> usb2).

Hi Volker,

There has been significant changes to ugen between usb and usb2.

It looks to me like that ugen started the transfer again after the USB 
transfer drain process started, so the drain will never exit. Probably it 
could need an extra flag there to catch that case, to prevent the start after 
trying to unsetup the transfer!

Try to turn on USB debugging:

sysctl hw.usb.debug=15

And grep for transfer start and stop.

--HPS