Read from bulk end point

[Hans Petter Selasky]

On Monday 27 June 2011 16:34:21 Luca Pizzamiglio wrote:
> Hi,
> 
> the buffer size mitigates the pre-fetch, but could not remove it all...
> Setting 1 as buffer size, the pre-fetch is reduces as 3 wMaxPacketSize
> IN transaction on the bus, but could not avoid it.
> 
> There is a way to disable pre-fetch features? Or better, HPS could you
> point me where is implemented? (just to save time studying source code!)
> 
> Is the prefetch also enabled for Interrupt end point? maybe I could have
> push to correctly redesign this USB board...
> 

Hi,

Have a look in sys/dev/usb/usb_generic.c

Also try to watch the traffic using usbdump.

--HPS

> thanks in advance!
> 
> Luca
> 
> On 06/27/11 13:20, Hans Petter Selasky wrote:
> > On Monday 27 June 2011 13:14:55 Luca Pizzamiglio wrote:
> >> It was strange, because for other endpoints I don't see this kind of
> >> behavior.
> > 
> > Hi,
> > 
> > That is perhaps because they send less data than wMaxPacketSize.
> > 
> > --HPS