[vbox-dev] USB EHCI support under Windows

[Hans Petter Selasky]

On Monday 22 August 2011 13:25:19 Bernhard Froehlich wrote:
> On Fri, 19 Aug 2011 17:02:12 +0200, Hans Petter Selasky wrote:
> > On Friday 22 July 2011 18:06:00 Hans Petter Selasky wrote:
> >> Hi,
> >> 
> >> There appears to be a bug when cancelling USB transactions (removing
> >> them from the EHCI schedule) on endpoints using the USB 2.0 mode, that
> >> the USB device is automatically re-enumerated. Who is responsible for
> >> this part? Is there any support available?
> > 
> > Hi,
> > 
> > Investigating this issue more properly, I see that VirtualBOX returns
> > an error
> > code when the Emulated OS tries to clear the stall on any endpoints. This
> > in turn cause the Emulated OS (FreeBSD) to re-enumerate the device.
> > 
> > Is this a bug or feature in VirtualBOX. Shouldn't clear-stall allways
> > succeed,
> > even if the data toggle value is not cared about?
> > 
> > --HPS
> > 
> > Fix for FreeBSD:
> > 
> > http://svn.freebsd.org/changeset/base/225000
> 
> Is this the problem that prevents USB sticks from beeing detected
> correctly on Linux guests? I never got any USB stick properly detected
> on Linux, FreeBSD or Windows 7 guests but we had quite a few success
> reports for input devices and Windows XP guests so it seems to work fine
> in some cases.

Hi,

I know UMASS is using clear-stall in some protocol error cases. If clear-stall 
cannot be executed, then there might be trouble, yes. This also depends on the 
memory stick brand I would guess.

--HPS