FT4232H on ehci problem (was Re: usb/143832: [uftdi] Request support for FTDI FT4232H.)

[Hans Petter Selasky]

On Monday 15 February 2010 15:00:56 Hans Petter Selasky wrote:
> On Monday 15 February 2010 14:37:10 UEMURA Tetsuya wrote:
> > > Now I have a problem with the device. When it is attached on ehci, it
> > > always stalls when I do a bit heavy communication over it. This doesn't
> > > happen with uhci (kldunload ehci or whatever).
> >
> > I did further investigation myself and found that wMaxPacketSize is
> > 0x0200 when the device was on ehci (0x0040 on uhci), and the device
> > seemed to work (at least not stall) on ehci if I changed
> > UFTDI_[IO]BUFSIZE to 512.
> >
> > The device however stopped working on uhci with such a modification.
> >
> > By the way, the official FTDI Linux driver found at
> > http://www.ftdichip.com/Drivers/VCP/Linux/ftdi_sio.tar.gz
> > also seemed to specify 512 as its buffer sizes.
> >
> > Can anyone help me?
> >
> > Regards.
> 
> What platform are you running?
> 
> --HPS
> 

There is a special feature in the new USB stack. Try to define:

#define UFTDI_IBUFSIZE 0  /* use wMaxPacketSize */

--HPS