Re: [9fans] usb serial bug

[erik quanstrom]

On Thu Feb 14 05:24:27 EST 2013, 9f...@hamnavoe.com wrote:
> > this is a WORKAROUND.  a proper fix would be something
> > like allowing ORDWR in usbopen if that is indeed the problem.
> 
> No, endpoints are unidirectional by design; in the usb spec there are
> no read/write endpoints.  The confusing thing in the spec is that two
> different endpoints can have the same endpoint number - they are
> distinguished by direction.  So what looks like a read/write endpoint
> number 1 is really two separate endpoints, input ep 1 and output ep 1.
> The current Plan 9 usb architecture perpetuates the confusion by
> referring to them both with one name epN.1, but you still have to open
> them both independently.
> 
> 

in that case, shouldn't these three blocks be reverted?

- erik

/n/dump/2012/1201/sys/src/cmd/usb/serial/serial.c:648,654 - 
/n/dump/2013/0212/sys/src/cmd/usb/serial/serial.c:647,657
                fprint(2, "serial: openep %d: %r\n", epin);
                return -1;
        }
-       p->epout = openep(ser->dev, epout);
+       if(epout == epin){
+               incref(p->epin);
+               p->epout = p->epin;
+       }else
+               p->epout = openep(ser->dev, epout);
        if(p->epout == nil){
                fprint(2, "serial: openep %d: %r\n", epout);
                closedev(p->epin);
/n/dump/2012/1201/sys/src/cmd/usb/serial/serial.c:674,681 - 
/n/dump/2013/0212/sys/src/cmd/usb/serial/serial.c:677,688
  
        if(ser->seteps!= nil)
                ser->seteps(p);
-       opendevdata(p->epin, OREAD);
-       opendevdata(p->epout, OWRITE);
+       if(p->epin == p->epout)
+               opendevdata(p->epin, ORDWR);
+       else{
+               opendevdata(p->epin, OREAD);
+               opendevdata(p->epout, OWRITE);
+       }
        if(p->epin->dfd < 0 ||p->epout->dfd < 0 ||
            (ser->hasepintr && p->epintr->dfd < 0)){
                fprint(2, "serial: open i/o ep data: %r\n");
/n/dump/2012/1201/sys/src/cmd/usb/serial/serial.c:709,717 - 
/n/dump/2013/0212/sys/src/cmd/usb/serial/serial.c:716,724
                    ep->dir == Ein && epintr == -1)
                        epintr = ep->id;
                if(ep->type == Ebulk){
-                       if(ep->dir == Ein && epin == -1)
+                       if((ep->dir == Ein || ep->dir == Eboth) && epin == -1)
                                epin = ep->id;
-                       if(ep->dir == Eout && epout == -1)
+                       if((ep->dir == Ein || ep->dir == Eboth) && epout == -1)
                                epout = ep->id;
                }
        }