On 4/4/07, Hans Petter Selasky <[EMAIL PROTECTED]> wrote:
> On Wednesday 04 April 2007 01:55, Xiaofan Chen wrote:
> > On 4/3/07, Hans Petter Selasky <[EMAIL PROTECTED]> wrote:
> > > Hi,
> > >
> > > I think that your device is broken, and goes bad when it receives a
> > > clear-stall request for the interrupt pipe. That is not very uncommon.
> >
> > Could you be more clearer? I'd like to communicate this problem
> > to the firmware developer of PICKit 2 inside Microchip. Thanks.
>
> The chip does not handle a clear-stall request on the control pipe to
> clear-stall on the interrupt pipe. The result is that the interrupt pipe
> stops, or at least all buffers are cleared.
>
> I could be more detailed, but I think the developers will understand what I
> mean.
>
Sorry to dig out this again. I read a bit more on the firmware source code
and I found the following. Seems a bit dubious. The USB controller used
is Microchip 18F2550.
Any comments? Thanks in advance.
/******************************************************************************
* Function: void USBStallHandler(void)
*
* PreCondition: A STALL packet is sent to the host by the SIE.
*
* Input: None
*
* Output: None
*
* Side Effects: None
*
* Overview: The STALLIF is set anytime the SIE sends out a STALL
* packet regardless of which endpoint causes it.
* A Setup transaction overrides the STALL function. A stalled
* endpoint stops stalling once it receives a setup packet.
* In this case, the SIE will accepts the Setup packet and
* set the TRNIF flag to notify the firmware. STALL function
* for that particular endpoint pipe will be automatically
* disabled (direction specific).
*
* There are a few reasons for an endpoint to be stalled.
* 1. When a non-supported USB request is received.
* Example: GET_DESCRIPTOR(DEVICE_QUALIFIER)
* 2. When an endpoint is currently halted.
* 3. When the device class specifies that an endpoint must
* stall in response to a specific event.
* Example: Mass Storage Device Class
* If the CBW is not valid, the device shall
* STALL the Bulk-In pipe.
* See USB Mass Storage Class Bulk-only Transport
* Specification for more details.
*
* Note: UEPn.EPSTALL can be scanned to see which endpoint causes
* the stall event.
* If
*****************************************************************************/
void USBStallHandler(void)
{
/*
* Does not really have to do anything here,
* even for the control endpoint.
* All BDs of Endpoint 0 are owned by SIE right now,
* but once a Setup Transaction is received, the ownership
* for EP0_OUT will be returned to CPU.
* When the Setup Transaction is serviced, the ownership
* for EP0_IN will then be forced back to CPU by firmware.
*
* NOTE: Above description is not quite true at this point.
* It seems the SIE never returns the UOWN bit to CPU,
* and a TRNIF is never generated upon successful
* reception of a SETUP transaction.
* Firmware work-around is implemented below.
*/
if(UEP0bits.EPSTALL == 1)
{
USBPrepareForNextSetupTrf(); // Firmware Work-Around
UEP0bits.EPSTALL = 0;
}
UIRbits.STALLIF = 0;
}//end USBStallHandler
/******************************************************************************
* Function: void USBPrepareForNextSetupTrf(void)
*
* PreCondition: None
*
* Input: None
*
* Output: None
*
* Side Effects: None
*
* Overview: The routine forces EP0 OUT to be ready for a new Setup
* transaction, and forces EP0 IN to be owned by CPU.
*
* Note: None
*****************************************************************************/
void USBPrepareForNextSetupTrf(void)
{
ctrl_trf_state = WAIT_SETUP; // See usbctrltrf.h
ep0Bo.Cnt = EP0_BUFF_SIZE; // Defined in usbcfg.h
ep0Bo.ADR = (byte*)&SetupPkt;
ep0Bo.Stat._byte = _USIE|_DAT0|_DTSEN; // EP0 buff dsc init, see usbmmap.h
ep0Bi.Stat._byte = _UCPU; // EP0 IN buffer initialization
}//end USBPrepareForNextSetupTrf
/** EOF usbctrltrf.c *********************************************************/
_______________________________________________
freebsd-usb@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-usb
To unsubscribe, send any mail to "[EMAIL PROTECTED]"
