libusb

On Mon, May 01, 2006 at 08:27:12PM +0200, Gerard Klaver wrote:
> Hello,
> 
> I have a question about usb commands, how to handle with libusb.
> I have for example the following sequence:
> 
> send urb 5, send urb 6, send/receive urb7, send/receive urb8, receive
> urb 5, receive urb6

You'll need to use asynchronous access, and you'll need to use the devel
branch of libusb.

- Chris

Hi,

On Mon, May 01, 2006 at 08:27:12PM +0200, Gerard Klaver wrote:
> send urb 5, send urb 6, send/receive urb7, send/receive urb8, receive
> urb 5, receive urb6
>=20
> At this moment i don't know how te handle this.
> send urb 5, 6 no problem, send/receive urb 7, 8 no problem, but how to
> handle to receive urb 5 and 6?.

Are you sure you need to do that btw? I've seen such sequences in
usbsnoop logs but all devices that I've tried have accepted different
ordering too. What type of URBs are those? Isochronous transfers?

best regards,
Timo Lindfors

Timo Juhani Lindfors wrote:

>Hi,
>
>On Mon, May 01, 2006 at 08:27:12PM +0200, Gerard Klaver wrote:
>  
>
>>send urb 5, send urb 6, send/receive urb7, send/receive urb8, receive
>>urb 5, receive urb6
>>
>>At this moment i don't know how te handle this.
>>send urb 5, 6 no problem, send/receive urb 7, 8 no problem, but how to
>>handle to receive urb 5 and 6?.
>>    
>>
>
>Are you sure you need to do that btw? I've seen such sequences in
>usbsnoop logs but all devices that I've tried have accepted different
>ordering too. What type of URBs are those? Isochronous transfers?
>  
>

Yes, it's not immediately clear to me what this means.  The only way you
can send and receive in a single URB is with a control pipe transfer,
and in that case it's synchronous.  So, if urbs 5 and 6 are bulk
transfers that trigger some bulk data later on, and 6 and 7 are control
transfers, I could see this scenario.  But in that case, there's really
no relationship between "send urb 5" and "receive urb 5".

-- 
Tim Roberts, timr@...
Providenza & Boekelheide, Inc.

On Thu, 2006-05-18 at 14:24 -0700, Tim Roberts wrote:
> Timo Juhani Lindfors wrote: 
> > Hi,
> > 
> > On Mon, May 01, 2006 at 08:27:12PM +0200, Gerard Klaver wrote:
> >   
> > > send urb 5, send urb 6, send/receive urb7, send/receive urb8, receive
> > > urb 5, receive urb6
> > > 
> > > At this moment i don't know how te handle this.
> > > send urb 5, 6 no problem, send/receive urb 7, 8 no problem, but how to
> > > handle to receive urb 5 and 6?.
> > >     
> > 
> > Are you sure you need to do that btw? I've seen such sequences in
> > usbsnoop logs but all devices that I've tried have accepted different
> > ordering too. What type of URBs are those? Isochronous transfers?
> >   
> 
> Yes, it's not immediately clear to me what this means.  The only way
> you can send and receive in a single URB is with a control pipe
> transfer, and in that case it's synchronous.  So, if urbs 5 and 6 are
> bulk transfers that trigger some bulk data later on, and 6 and 7 are
> control transfers, I could see this scenario.  But in that case,
> there's really no relationship between "send urb 5" and "receive urb
> 5".
> -- 
> Tim Roberts, timr@...
> Providenza & Boekelheide, Inc.


urb 5, 6 are bulk read transfers, urb 7 and 8 are bulk write transfers

-- 
--------
m.vr.gr.
Gerard Klaver