xref: /openbsd-src/sys/dev/usb/uhub.c (revision 9f5f6d504a0cbb684120cfba32c9bc24deaf87fa)
1 /*	$OpenBSD: uhub.c,v 1.47 2007/06/14 10:11:16 mbalmer Exp $ */
2 /*	$NetBSD: uhub.c,v 1.64 2003/02/08 03:32:51 ichiro Exp $	*/
3 /*	$FreeBSD: src/sys/dev/usb/uhub.c,v 1.18 1999/11/17 22:33:43 n_hibma Exp $	*/
4 
5 /*
6  * Copyright (c) 1998 The NetBSD Foundation, Inc.
7  * All rights reserved.
8  *
9  * This code is derived from software contributed to The NetBSD Foundation
10  * by Lennart Augustsson (lennart@augustsson.net) at
11  * Carlstedt Research & Technology.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. All advertising materials mentioning features or use of this software
22  *    must display the following acknowledgement:
23  *        This product includes software developed by the NetBSD
24  *        Foundation, Inc. and its contributors.
25  * 4. Neither the name of The NetBSD Foundation nor the names of its
26  *    contributors may be used to endorse or promote products derived
27  *    from this software without specific prior written permission.
28  *
29  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
30  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
31  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
32  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
33  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
34  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
35  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
36  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
37  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
38  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
39  * POSSIBILITY OF SUCH DAMAGE.
40  */
41 
42 /*
43  * USB spec: http://www.usb.org/developers/docs/usbspec.zip
44  */
45 
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/kernel.h>
49 #include <sys/malloc.h>
50 #include <sys/device.h>
51 #include <sys/proc.h>
52 
53 #include <machine/bus.h>
54 
55 #include <dev/usb/usb.h>
56 #include <dev/usb/usbdi.h>
57 #include <dev/usb/usbdi_util.h>
58 #include <dev/usb/usbdivar.h>
59 
60 #define UHUB_INTR_INTERVAL 255	/* ms */
61 
62 #ifdef UHUB_DEBUG
63 #define DPRINTF(x)	do { if (uhubdebug) printf x; } while (0)
64 #define DPRINTFN(n,x)	do { if (uhubdebug>(n)) printf x; } while (0)
65 int	uhubdebug = 0;
66 #else
67 #define DPRINTF(x)
68 #define DPRINTFN(n,x)
69 #endif
70 
71 struct uhub_softc {
72 	struct device		sc_dev;		/* base device */
73 	usbd_device_handle	sc_hub;		/* USB device */
74 	usbd_pipe_handle	sc_ipipe;	/* interrupt pipe */
75 	u_int8_t		sc_status[1];	/* XXX more ports */
76 	u_char			sc_running;
77 };
78 #define UHUB_PROTO(sc) ((sc)->sc_hub->ddesc.bDeviceProtocol)
79 #define UHUB_IS_HIGH_SPEED(sc) (UHUB_PROTO(sc) != UDPROTO_FSHUB)
80 #define UHUB_IS_SINGLE_TT(sc) (UHUB_PROTO(sc) == UDPROTO_HSHUBSTT)
81 
82 usbd_status uhub_explore(usbd_device_handle hub);
83 void uhub_intr(usbd_xfer_handle, usbd_private_handle,usbd_status);
84 
85 /*
86  * We need two attachment points:
87  * hub to usb and hub to hub
88  * Every other driver only connects to hubs
89  */
90 
91 int uhub_match(struct device *, void *, void *);
92 void uhub_attach(struct device *, struct device *, void *);
93 int uhub_detach(struct device *, int);
94 int uhub_activate(struct device *, enum devact);
95 
96 struct cfdriver uhub_cd = {
97 	NULL, "uhub", DV_DULL
98 };
99 
100 const struct cfattach uhub_ca = {
101 	sizeof(struct uhub_softc),
102 	uhub_match,
103 	uhub_attach,
104 	uhub_detach,
105 	uhub_activate,
106 };
107 
108 struct cfattach uhub_uhub_ca = {
109 	sizeof(struct uhub_softc), uhub_match, uhub_attach,
110 	uhub_detach, uhub_activate
111 };
112 
113 int
114 uhub_match(struct device *parent, void *match, void *aux)
115 {
116 	struct usb_attach_arg *uaa = aux;
117 	usb_device_descriptor_t *dd = usbd_get_device_descriptor(uaa->device);
118 
119 	DPRINTFN(5,("uhub_match, dd=%p\n", dd));
120 	/*
121 	 * The subclass for hubs seems to be 0 for some and 1 for others,
122 	 * so we just ignore the subclass.
123 	 */
124 	if (uaa->iface == NULL && dd->bDeviceClass == UDCLASS_HUB)
125 		return (UMATCH_DEVCLASS_DEVSUBCLASS);
126 	return (UMATCH_NONE);
127 }
128 
129 void
130 uhub_attach(struct device *parent, struct device *self, void *aux)
131 {
132 	struct uhub_softc *sc = (struct uhub_softc *)self;
133 	struct usb_attach_arg *uaa = aux;
134 	usbd_device_handle dev = uaa->device;
135 	char *devinfop;
136 	usbd_status err;
137 	struct usbd_hub *hub = NULL;
138 	usb_device_request_t req;
139 	usb_hub_descriptor_t hubdesc;
140 	int p, port, nports, nremov, pwrdly;
141 	usbd_interface_handle iface;
142 	usb_endpoint_descriptor_t *ed;
143 	struct usbd_tt *tts = NULL;
144 
145 	DPRINTFN(1,("uhub_attach\n"));
146 	sc->sc_hub = dev;
147 
148 	devinfop = usbd_devinfo_alloc(dev, 0);
149 	printf(": %s\n", devinfop);
150 	usbd_devinfo_free(devinfop);
151 
152 	err = usbd_set_config_index(dev, 0, 1);
153 	if (err) {
154 		DPRINTF(("%s: configuration failed, error=%s\n",
155 			 sc->sc_dev.dv_xname, usbd_errstr(err)));
156 		return;
157 	}
158 
159 	if (dev->depth > USB_HUB_MAX_DEPTH) {
160 		printf("%s: hub depth (%d) exceeded, hub ignored\n",
161 		       sc->sc_dev.dv_xname, USB_HUB_MAX_DEPTH);
162 		return;
163 	}
164 
165 	/* Get hub descriptor. */
166 	req.bmRequestType = UT_READ_CLASS_DEVICE;
167 	req.bRequest = UR_GET_DESCRIPTOR;
168 	USETW2(req.wValue, UDESC_HUB, 0);
169 	USETW(req.wIndex, 0);
170 	USETW(req.wLength, USB_HUB_DESCRIPTOR_SIZE);
171 	DPRINTFN(1,("usb_init_hub: getting hub descriptor\n"));
172 	err = usbd_do_request(dev, &req, &hubdesc);
173 	nports = hubdesc.bNbrPorts;
174 	if (!err && nports > 7) {
175 		USETW(req.wLength, USB_HUB_DESCRIPTOR_SIZE + (nports+1) / 8);
176 		err = usbd_do_request(dev, &req, &hubdesc);
177 	}
178 	if (err) {
179 		DPRINTF(("%s: getting hub descriptor failed, error=%s\n",
180 			 sc->sc_dev.dv_xname, usbd_errstr(err)));
181 		return;
182 	}
183 
184 	for (nremov = 0, port = 1; port <= nports; port++)
185 		if (!UHD_NOT_REMOV(&hubdesc, port))
186 			nremov++;
187 
188 #ifdef UHUB_DEBUG
189 	printf("%s: %d port%s with %d removable, %s powered",
190 	       sc->sc_dev.dv_xname, nports, nports != 1 ? "s" : "",
191 	       nremov, dev->self_powered ? "self" : "bus");
192 
193 	if (dev->depth > 0 && UHUB_IS_HIGH_SPEED(sc)) {
194 		printf(", %s transaction translator%s",
195 		    UHUB_IS_SINGLE_TT(sc) ? "single" : "multiple",
196 		    UHUB_IS_SINGLE_TT(sc) ? "" : "s");
197 	}
198 	printf("\n");
199 #endif
200 
201 	if (nports == 0) {
202 		printf("%s: no ports, hub ignored\n", sc->sc_dev.dv_xname);
203 		goto bad;
204 	}
205 
206 	hub = malloc(sizeof(*hub) + (nports-1) * sizeof(struct usbd_port),
207 		     M_USBDEV, M_NOWAIT);
208 	if (hub == NULL)
209 		return;
210 	dev->hub = hub;
211 	dev->hub->hubsoftc = sc;
212 	hub->explore = uhub_explore;
213 	hub->hubdesc = hubdesc;
214 
215 	DPRINTFN(1,("usbhub_init_hub: selfpowered=%d, parent=%p, "
216 		    "parent->selfpowered=%d\n",
217 		 dev->self_powered, dev->powersrc->parent,
218 		 dev->powersrc->parent ?
219 		 dev->powersrc->parent->self_powered : 0));
220 
221 	if (!dev->self_powered && dev->powersrc->parent != NULL &&
222 	    !dev->powersrc->parent->self_powered) {
223 		printf("%s: bus powered hub connected to bus powered hub, "
224 		       "ignored\n", sc->sc_dev.dv_xname);
225 		goto bad;
226 	}
227 
228 	/* Set up interrupt pipe. */
229 	err = usbd_device2interface_handle(dev, 0, &iface);
230 	if (err) {
231 		printf("%s: no interface handle\n", sc->sc_dev.dv_xname);
232 		goto bad;
233 	}
234 	ed = usbd_interface2endpoint_descriptor(iface, 0);
235 	if (ed == NULL) {
236 		printf("%s: no endpoint descriptor\n", sc->sc_dev.dv_xname);
237 		goto bad;
238 	}
239 	if ((ed->bmAttributes & UE_XFERTYPE) != UE_INTERRUPT) {
240 		printf("%s: bad interrupt endpoint\n", sc->sc_dev.dv_xname);
241 		goto bad;
242 	}
243 
244 	err = usbd_open_pipe_intr(iface, ed->bEndpointAddress,
245 		  USBD_SHORT_XFER_OK, &sc->sc_ipipe, sc, sc->sc_status,
246 		  sizeof(sc->sc_status), uhub_intr, UHUB_INTR_INTERVAL);
247 	if (err) {
248 		printf("%s: cannot open interrupt pipe\n",
249 		       sc->sc_dev.dv_xname);
250 		goto bad;
251 	}
252 
253 	/* Wait with power off for a while. */
254 	usbd_delay_ms(dev, USB_POWER_DOWN_TIME);
255 
256 	usbd_add_drv_event(USB_EVENT_DRIVER_ATTACH, dev, &sc->sc_dev);
257 
258 	/*
259 	 * To have the best chance of success we do things in the exact same
260 	 * order as Windoze98.  This should not be necessary, but some
261 	 * devices do not follow the USB specs to the letter.
262 	 *
263 	 * These are the events on the bus when a hub is attached:
264 	 *  Get device and config descriptors (see attach code)
265 	 *  Get hub descriptor (see above)
266 	 *  For all ports
267 	 *     turn on power
268 	 *     wait for power to become stable
269 	 * (all below happens in explore code)
270 	 *  For all ports
271 	 *     clear C_PORT_CONNECTION
272 	 *  For all ports
273 	 *     get port status
274 	 *     if device connected
275 	 *        wait 100 ms
276 	 *        turn on reset
277 	 *        wait
278 	 *        clear C_PORT_RESET
279 	 *        get port status
280 	 *        proceed with device attachment
281 	 */
282 
283 	if (UHUB_IS_HIGH_SPEED(sc)) {
284 		tts = malloc((UHUB_IS_SINGLE_TT(sc) ? 1 : nports) *
285 		    sizeof (struct usbd_tt), M_USBDEV, M_NOWAIT);
286 		if (!tts)
287 			goto bad;
288 	}
289 	/* Set up data structures */
290 	for (p = 0; p < nports; p++) {
291 		struct usbd_port *up = &hub->ports[p];
292 		up->device = NULL;
293 		up->parent = dev;
294 		up->portno = p+1;
295 		if (dev->self_powered)
296 			/* Self powered hub, give ports maximum current. */
297 			up->power = USB_MAX_POWER;
298 		else
299 			up->power = USB_MIN_POWER;
300 		up->restartcnt = 0;
301 		up->reattach = 0;
302 		if (UHUB_IS_HIGH_SPEED(sc)) {
303 			up->tt = &tts[UHUB_IS_SINGLE_TT(sc) ? 0 : p];
304 			up->tt->hub = hub;
305 		} else {
306 			up->tt = NULL;
307 		}
308 	}
309 
310 	/* XXX should check for none, individual, or ganged power? */
311 
312 	pwrdly = dev->hub->hubdesc.bPwrOn2PwrGood * UHD_PWRON_FACTOR
313 	    + USB_EXTRA_POWER_UP_TIME;
314 	for (port = 1; port <= nports; port++) {
315 		/* Turn the power on. */
316 		err = usbd_set_port_feature(dev, port, UHF_PORT_POWER);
317 		if (err)
318 			printf("%s: port %d power on failed, %s\n",
319 			       sc->sc_dev.dv_xname, port,
320 			       usbd_errstr(err));
321 		DPRINTF(("usb_init_port: turn on port %d power\n", port));
322 	}
323 
324 	/* Wait for stable power.  Root hubs delay in their event thread. */
325         if (dev->powersrc->parent != NULL)
326 		usbd_delay_ms(dev, pwrdly);
327 
328 	/* The usual exploration will finish the setup. */
329 
330 	sc->sc_running = 1;
331 
332 	return;
333 
334  bad:
335 	if (hub)
336 		free(hub, M_USBDEV);
337 	dev->hub = NULL;
338 }
339 
340 usbd_status
341 uhub_explore(usbd_device_handle dev)
342 {
343 	usb_hub_descriptor_t *hd = &dev->hub->hubdesc;
344 	struct uhub_softc *sc = dev->hub->hubsoftc;
345 	struct usbd_port *up;
346 	usbd_status err;
347 	int speed;
348 	int port;
349 	int change, status, reconnect;
350 
351 	DPRINTFN(10, ("uhub_explore dev=%p addr=%d\n", dev, dev->address));
352 
353 	if (!sc->sc_running)
354 		return (USBD_NOT_STARTED);
355 
356 	/* Ignore hubs that are too deep. */
357 	if (dev->depth > USB_HUB_MAX_DEPTH)
358 		return (USBD_TOO_DEEP);
359 
360 	for(port = 1; port <= hd->bNbrPorts; port++) {
361 		up = &dev->hub->ports[port-1];
362 		err = usbd_get_port_status(dev, port, &up->status);
363 		if (err) {
364 			DPRINTF(("uhub_explore: get port status failed, "
365 				 "error=%s\n", usbd_errstr(err)));
366 			continue;
367 		}
368 		status = UGETW(up->status.wPortStatus);
369 		change = UGETW(up->status.wPortChange);
370 		reconnect = up->reattach;
371 		up->reattach = 0;
372 		DPRINTFN(3,("uhub_explore: %s port %d status 0x%04x 0x%04x\n",
373 			    sc->sc_dev.dv_xname, port, status, change));
374 		if (change & UPS_C_PORT_ENABLED) {
375 			DPRINTF(("uhub_explore: C_PORT_ENABLED\n"));
376 			usbd_clear_port_feature(dev, port, UHF_C_PORT_ENABLE);
377 			if (change & UPS_C_CONNECT_STATUS) {
378 				/* Ignore the port error if the device
379 				   vanished. */
380 			} else if (status & UPS_PORT_ENABLED) {
381 				printf("%s: illegal enable change, port %d\n",
382 				       sc->sc_dev.dv_xname, port);
383 			} else {
384 				/* Port error condition. */
385 				if (up->restartcnt) /* no message first time */
386 					printf("%s: port error, restarting "
387 					       "port %d\n",
388 					       sc->sc_dev.dv_xname, port);
389 
390 				if (up->restartcnt++ < USBD_RESTART_MAX)
391 					goto disco;
392 				else
393 					printf("%s: port error, giving up "
394 					       "port %d\n",
395 					       sc->sc_dev.dv_xname, port);
396 			}
397 		}
398 		if (!reconnect && !(change & UPS_C_CONNECT_STATUS)) {
399 			DPRINTFN(3,("uhub_explore: port=%d !C_CONNECT_"
400 				    "STATUS\n", port));
401 			/* No status change, just do recursive explore. */
402 			if (up->device != NULL && up->device->hub != NULL)
403 				up->device->hub->explore(up->device);
404 #if 0 && defined(DIAGNOSTIC)
405 			if (up->device == NULL &&
406 			    (status & UPS_CURRENT_CONNECT_STATUS))
407 				printf("%s: connected, no device\n",
408 				       sc->sc_dev.dv_xname);
409 #endif
410 			continue;
411 		}
412 
413 		/* We have a connect status change, handle it. */
414 
415 		DPRINTF(("uhub_explore: status change hub=%d port=%d\n",
416 			 dev->address, port));
417 		usbd_clear_port_feature(dev, port, UHF_C_PORT_CONNECTION);
418 		/*usbd_clear_port_feature(dev, port, UHF_C_PORT_ENABLE);*/
419 		/*
420 		 * If there is already a device on the port the change status
421 		 * must mean that is has disconnected.  Looking at the
422 		 * current connect status is not enough to figure this out
423 		 * since a new unit may have been connected before we handle
424 		 * the disconnect.
425 		 */
426 	disco:
427 		if (up->device != NULL) {
428 			/* Disconnected */
429 			DPRINTF(("uhub_explore: device addr=%d disappeared "
430 				 "on port %d\n", up->device->address, port));
431 			usb_disconnect_port(up, &sc->sc_dev);
432 			usbd_clear_port_feature(dev, port,
433 						UHF_C_PORT_CONNECTION);
434 		}
435 		if (!(status & UPS_CURRENT_CONNECT_STATUS)) {
436 			/* Nothing connected, just ignore it. */
437 			DPRINTFN(3,("uhub_explore: port=%d !CURRENT_CONNECT"
438 				    "_STATUS\n", port));
439 			continue;
440 		}
441 
442 		/* Connected */
443 
444 		if (!(status & UPS_PORT_POWER))
445 			printf("%s: strange, connected port %d has no power\n",
446 			       sc->sc_dev.dv_xname, port);
447 
448 		/* Wait for maximum device power up time. */
449 		usbd_delay_ms(dev, USB_PORT_POWERUP_DELAY);
450 
451 		/* Reset port, which implies enabling it. */
452 		if (usbd_reset_port(dev, port, &up->status)) {
453 			printf("%s: port %d reset failed\n",
454 			       sc->sc_dev.dv_xname, port);
455 			continue;
456 		}
457 		/* Get port status again, it might have changed during reset */
458 		err = usbd_get_port_status(dev, port, &up->status);
459 		if (err) {
460 			DPRINTF(("uhub_explore: get port status failed, "
461 				 "error=%s\n", usbd_errstr(err)));
462 			continue;
463 		}
464 		status = UGETW(up->status.wPortStatus);
465 		change = UGETW(up->status.wPortChange);
466 		if (!(status & UPS_CURRENT_CONNECT_STATUS)) {
467 			/* Nothing connected, just ignore it. */
468 #ifdef UHUB_DEBUG
469 			printf("%s: port %d, device disappeared after reset\n",
470 			       sc->sc_dev.dv_xname, port);
471 #endif
472 			continue;
473 		}
474 
475 		/* Figure out device speed */
476 		if (status & UPS_HIGH_SPEED)
477 			speed = USB_SPEED_HIGH;
478 		else if (status & UPS_LOW_SPEED)
479 			speed = USB_SPEED_LOW;
480 		else
481 			speed = USB_SPEED_FULL;
482 		/* Get device info and set its address. */
483 		err = usbd_new_device(&sc->sc_dev, dev->bus,
484 			  dev->depth + 1, speed, port, up);
485 		/* XXX retry a few times? */
486 		if (err) {
487 			DPRINTFN(-1,("uhub_explore: usbd_new_device failed, "
488 				     "error=%s\n", usbd_errstr(err)));
489 			/* Avoid addressing problems by disabling. */
490 			/* usbd_reset_port(dev, port, &up->status); */
491 
492 			/*
493 			 * The unit refused to accept a new address, or had
494 			 * some other serious problem.  Since we cannot leave
495 			 * at 0 we have to disable the port instead.
496 			 */
497 			printf("%s: device problem, disabling port %d\n",
498 			       sc->sc_dev.dv_xname, port);
499 			usbd_clear_port_feature(dev, port, UHF_PORT_ENABLE);
500 		} else {
501 			/* The port set up succeeded, reset error count. */
502 			up->restartcnt = 0;
503 
504 			if (up->device->hub)
505 				up->device->hub->explore(up->device);
506 		}
507 	}
508 	return (USBD_NORMAL_COMPLETION);
509 }
510 
511 int
512 uhub_activate(struct device *self, enum devact act)
513 {
514 	struct uhub_softc *sc = (struct uhub_softc *)self;
515 	struct usbd_hub *hub = sc->sc_hub->hub;
516 	usbd_device_handle dev;
517 	int nports, port, i;
518 
519 	switch (act) {
520 	case DVACT_ACTIVATE:
521 		break;
522 
523 	case DVACT_DEACTIVATE:
524 		if (hub == NULL) /* malfunctioning hub */
525 			break;
526 		nports = hub->hubdesc.bNbrPorts;
527 		for(port = 0; port < nports; port++) {
528 			dev = hub->ports[port].device;
529 			if (dev != NULL && dev->subdevs != NULL) {
530 				for (i = 0; dev->subdevs[i] != NULL; i++)
531 					config_deactivate(dev->subdevs[i]);
532 			}
533 		}
534 		break;
535 	}
536 	return (0);
537 }
538 
539 /*
540  * Called from process context when the hub is gone.
541  * Detach all devices on active ports.
542  */
543 int
544 uhub_detach(struct device *self, int flags)
545 {
546 	struct uhub_softc *sc = (struct uhub_softc *)self;
547 	struct usbd_hub *hub = sc->sc_hub->hub;
548 	struct usbd_port *rup;
549 	int port, nports;
550 
551 	DPRINTF(("uhub_detach: sc=%p flags=%d\n", sc, flags));
552 
553 	if (hub == NULL)		/* Must be partially working */
554 		return (0);
555 
556 	usbd_abort_pipe(sc->sc_ipipe);
557 	usbd_close_pipe(sc->sc_ipipe);
558 
559 	nports = hub->hubdesc.bNbrPorts;
560 	for(port = 0; port < nports; port++) {
561 		rup = &hub->ports[port];
562 		if (rup->device)
563 			usb_disconnect_port(rup, self);
564 	}
565 
566 	usbd_add_drv_event(USB_EVENT_DRIVER_DETACH, sc->sc_hub,
567 			   &sc->sc_dev);
568 
569 	if (hub->ports[0].tt)
570 		free(hub->ports[0].tt, M_USBDEV);
571 	free(hub, M_USBDEV);
572 	sc->sc_hub->hub = NULL;
573 
574 	return (0);
575 }
576 
577 /*
578  * Hub interrupt.
579  * This an indication that some port has changed status.
580  * Notify the bus event handler thread that we need
581  * to be explored again.
582  */
583 void
584 uhub_intr(usbd_xfer_handle xfer, usbd_private_handle addr, usbd_status status)
585 {
586 	struct uhub_softc *sc = addr;
587 
588 	DPRINTFN(5,("uhub_intr: sc=%p\n", sc));
589 	if (status == USBD_STALLED)
590 		usbd_clear_endpoint_stall_async(sc->sc_ipipe);
591 	else if (status == USBD_NORMAL_COMPLETION)
592 		usb_needs_explore(sc->sc_hub);
593 }
594