xref: /openbsd-src/sys/dev/usb/uhub.c (revision ac9b4aacc1da35008afea06a5d23c2f2dea9b93e)
1 /*	$OpenBSD: uhub.c,v 1.59 2011/09/29 11:18:01 stsp 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  *
22  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
24  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
25  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
26  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32  * POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 /*
36  * USB spec: http://www.usb.org/developers/docs/usbspec.zip
37  */
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/kernel.h>
42 #include <sys/malloc.h>
43 #include <sys/device.h>
44 #include <sys/proc.h>
45 
46 #include <machine/bus.h>
47 
48 #include <dev/usb/usb.h>
49 #include <dev/usb/usbdi.h>
50 #include <dev/usb/usbdi_util.h>
51 #include <dev/usb/usbdivar.h>
52 
53 #define UHUB_INTR_INTERVAL 255	/* ms */
54 
55 #ifdef UHUB_DEBUG
56 #define DPRINTF(x)	do { if (uhubdebug) printf x; } while (0)
57 #define DPRINTFN(n,x)	do { if (uhubdebug>(n)) printf x; } while (0)
58 int	uhubdebug = 0;
59 #else
60 #define DPRINTF(x)
61 #define DPRINTFN(n,x)
62 #endif
63 
64 struct uhub_softc {
65 	struct device		sc_dev;		/* base device */
66 	usbd_device_handle	sc_hub;		/* USB device */
67 	usbd_pipe_handle	sc_ipipe;	/* interrupt pipe */
68 	u_int8_t		*sc_statusbuf;	/* per port status buffer */
69 	size_t			sc_statuslen;	/* status bufferlen */
70 	u_char			sc_running;
71 };
72 #define UHUB_PROTO(sc) ((sc)->sc_hub->ddesc.bDeviceProtocol)
73 #define UHUB_IS_HIGH_SPEED(sc) (UHUB_PROTO(sc) != UDPROTO_FSHUB)
74 #define UHUB_IS_SINGLE_TT(sc) (UHUB_PROTO(sc) == UDPROTO_HSHUBSTT)
75 
76 usbd_status uhub_explore(usbd_device_handle hub);
77 void uhub_intr(usbd_xfer_handle, usbd_private_handle,usbd_status);
78 
79 /*
80  * We need two attachment points:
81  * hub to usb and hub to hub
82  * Every other driver only connects to hubs
83  */
84 
85 int uhub_match(struct device *, void *, void *);
86 void uhub_attach(struct device *, struct device *, void *);
87 int uhub_detach(struct device *, int);
88 int uhub_activate(struct device *, int);
89 
90 struct cfdriver uhub_cd = {
91 	NULL, "uhub", DV_DULL
92 };
93 
94 const struct cfattach uhub_ca = {
95 	sizeof(struct uhub_softc),
96 	uhub_match,
97 	uhub_attach,
98 	uhub_detach,
99 	uhub_activate,
100 };
101 
102 struct cfattach uhub_uhub_ca = {
103 	sizeof(struct uhub_softc), uhub_match, uhub_attach,
104 	uhub_detach, uhub_activate
105 };
106 
107 int
108 uhub_match(struct device *parent, void *match, void *aux)
109 {
110 	struct usb_attach_arg *uaa = aux;
111 	usb_device_descriptor_t *dd = usbd_get_device_descriptor(uaa->device);
112 
113 	DPRINTFN(5,("uhub_match, dd=%p\n", dd));
114 	/*
115 	 * The subclass for hubs seems to be 0 for some and 1 for others,
116 	 * so we just ignore the subclass.
117 	 */
118 	if (uaa->iface == NULL && dd->bDeviceClass == UDCLASS_HUB)
119 		return (UMATCH_DEVCLASS_DEVSUBCLASS);
120 	return (UMATCH_NONE);
121 }
122 
123 void
124 uhub_attach(struct device *parent, struct device *self, void *aux)
125 {
126 	struct uhub_softc *sc = (struct uhub_softc *)self;
127 	struct usb_attach_arg *uaa = aux;
128 	usbd_device_handle dev = uaa->device;
129 	usbd_status err;
130 	struct usbd_hub *hub = NULL;
131 	usb_device_request_t req;
132 	usb_hub_descriptor_t hubdesc;
133 	int p, port, nports, nremov, pwrdly;
134 	usbd_interface_handle iface;
135 	usb_endpoint_descriptor_t *ed;
136 	struct usbd_tt *tts = NULL;
137 
138 	DPRINTFN(1,("uhub_attach\n"));
139 	sc->sc_hub = dev;
140 
141 	err = usbd_set_config_index(dev, 0, 1);
142 	if (err) {
143 		DPRINTF(("%s: configuration failed, error=%s\n",
144 			 sc->sc_dev.dv_xname, usbd_errstr(err)));
145 		return;
146 	}
147 
148 	if (dev->depth > USB_HUB_MAX_DEPTH) {
149 		printf("%s: hub depth (%d) exceeded, hub ignored\n",
150 		       sc->sc_dev.dv_xname, USB_HUB_MAX_DEPTH);
151 		return;
152 	}
153 
154 	/* Get hub descriptor. */
155 	req.bmRequestType = UT_READ_CLASS_DEVICE;
156 	req.bRequest = UR_GET_DESCRIPTOR;
157 	USETW2(req.wValue, UDESC_HUB, 0);
158 	USETW(req.wIndex, 0);
159 	USETW(req.wLength, USB_HUB_DESCRIPTOR_SIZE);
160 	DPRINTFN(1,("usb_init_hub: getting hub descriptor\n"));
161 	err = usbd_do_request(dev, &req, &hubdesc);
162 	nports = hubdesc.bNbrPorts;
163 	if (!err && nports > 7) {
164 		USETW(req.wLength, USB_HUB_DESCRIPTOR_SIZE + (nports+1) / 8);
165 		err = usbd_do_request(dev, &req, &hubdesc);
166 	}
167 	if (err) {
168 		DPRINTF(("%s: getting hub descriptor failed, error=%s\n",
169 			 sc->sc_dev.dv_xname, usbd_errstr(err)));
170 		return;
171 	}
172 
173 	for (nremov = 0, port = 1; port <= nports; port++)
174 		if (!UHD_NOT_REMOV(&hubdesc, port))
175 			nremov++;
176 
177 #ifdef UHUB_DEBUG
178 	printf("%s: %d port%s with %d removable, %s powered",
179 	       sc->sc_dev.dv_xname, nports, nports != 1 ? "s" : "",
180 	       nremov, dev->self_powered ? "self" : "bus");
181 
182 	if (dev->depth > 0 && UHUB_IS_HIGH_SPEED(sc)) {
183 		printf(", %s transaction translator%s",
184 		    UHUB_IS_SINGLE_TT(sc) ? "single" : "multiple",
185 		    UHUB_IS_SINGLE_TT(sc) ? "" : "s");
186 	}
187 	printf("\n");
188 #endif
189 
190 	if (nports == 0) {
191 		printf("%s: no ports, hub ignored\n", sc->sc_dev.dv_xname);
192 		goto bad;
193 	}
194 
195 	hub = malloc(sizeof(*hub), M_USBDEV, M_NOWAIT);
196 	if (hub == NULL)
197 		return;
198 	hub->ports = malloc(sizeof(struct usbd_port) * nports,
199 	    M_USBDEV, M_NOWAIT);
200 	if (hub->ports == NULL) {
201 		free(hub, M_USBDEV);
202 		return;
203 	}
204 	dev->hub = hub;
205 	dev->hub->hubsoftc = sc;
206 	hub->explore = uhub_explore;
207 	hub->hubdesc = hubdesc;
208 
209 	DPRINTFN(1,("usbhub_init_hub: selfpowered=%d, parent=%p, "
210 		    "parent->selfpowered=%d\n",
211 		 dev->self_powered, dev->powersrc->parent,
212 		 dev->powersrc->parent ?
213 		 dev->powersrc->parent->self_powered : 0));
214 
215 	if (!dev->self_powered && dev->powersrc->parent != NULL &&
216 	    !dev->powersrc->parent->self_powered) {
217 		printf("%s: bus powered hub connected to bus powered hub, "
218 		       "ignored\n", sc->sc_dev.dv_xname);
219 		goto bad;
220 	}
221 
222 	/* Set up interrupt pipe. */
223 	err = usbd_device2interface_handle(dev, 0, &iface);
224 	if (err) {
225 		printf("%s: no interface handle\n", sc->sc_dev.dv_xname);
226 		goto bad;
227 	}
228 	ed = usbd_interface2endpoint_descriptor(iface, 0);
229 	if (ed == NULL) {
230 		printf("%s: no endpoint descriptor\n", sc->sc_dev.dv_xname);
231 		goto bad;
232 	}
233 	if ((ed->bmAttributes & UE_XFERTYPE) != UE_INTERRUPT) {
234 		printf("%s: bad interrupt endpoint\n", sc->sc_dev.dv_xname);
235 		goto bad;
236 	}
237 
238 	sc->sc_statuslen = (nports + 1 + 7) / 8;
239 	sc->sc_statusbuf = malloc(sc->sc_statuslen, M_USBDEV, M_NOWAIT);
240 	if (!sc->sc_statusbuf)
241 		goto bad;
242 
243 	err = usbd_open_pipe_intr(iface, ed->bEndpointAddress,
244 		  USBD_SHORT_XFER_OK, &sc->sc_ipipe, sc, sc->sc_statusbuf,
245 		  sc->sc_statuslen, uhub_intr, UHUB_INTR_INTERVAL);
246 	if (err) {
247 		printf("%s: cannot open interrupt pipe\n",
248 		       sc->sc_dev.dv_xname);
249 		goto bad;
250 	}
251 
252 	/* Wait with power off for a while. */
253 	usbd_delay_ms(dev, USB_POWER_DOWN_TIME);
254 
255 	/*
256 	 * To have the best chance of success we do things in the exact same
257 	 * order as Windoze98.  This should not be necessary, but some
258 	 * devices do not follow the USB specs to the letter.
259 	 *
260 	 * These are the events on the bus when a hub is attached:
261 	 *  Get device and config descriptors (see attach code)
262 	 *  Get hub descriptor (see above)
263 	 *  For all ports
264 	 *     turn on power
265 	 *     wait for power to become stable
266 	 * (all below happens in explore code)
267 	 *  For all ports
268 	 *     clear C_PORT_CONNECTION
269 	 *  For all ports
270 	 *     get port status
271 	 *     if device connected
272 	 *        wait 100 ms
273 	 *        turn on reset
274 	 *        wait
275 	 *        clear C_PORT_RESET
276 	 *        get port status
277 	 *        proceed with device attachment
278 	 */
279 
280 	if (UHUB_IS_HIGH_SPEED(sc)) {
281 		tts = malloc((UHUB_IS_SINGLE_TT(sc) ? 1 : nports) *
282 		    sizeof (struct usbd_tt), M_USBDEV, M_NOWAIT);
283 		if (!tts)
284 			goto bad;
285 	}
286 	/* Set up data structures */
287 	for (p = 0; p < nports; p++) {
288 		struct usbd_port *up = &hub->ports[p];
289 		up->device = NULL;
290 		up->parent = dev;
291 		up->portno = p+1;
292 		if (dev->self_powered)
293 			/* Self powered hub, give ports maximum current. */
294 			up->power = USB_MAX_POWER;
295 		else
296 			up->power = USB_MIN_POWER;
297 		up->restartcnt = 0;
298 		up->reattach = 0;
299 		if (UHUB_IS_HIGH_SPEED(sc)) {
300 			up->tt = &tts[UHUB_IS_SINGLE_TT(sc) ? 0 : p];
301 			up->tt->hub = hub;
302 		} else {
303 			up->tt = NULL;
304 		}
305 	}
306 
307 	/* XXX should check for none, individual, or ganged power? */
308 
309 	pwrdly = dev->hub->hubdesc.bPwrOn2PwrGood * UHD_PWRON_FACTOR
310 	    + USB_EXTRA_POWER_UP_TIME;
311 	for (port = 1; port <= nports; port++) {
312 		/* Turn the power on. */
313 		err = usbd_set_port_feature(dev, port, UHF_PORT_POWER);
314 		if (err)
315 			printf("%s: port %d power on failed, %s\n",
316 			       sc->sc_dev.dv_xname, port,
317 			       usbd_errstr(err));
318 		DPRINTF(("usb_init_port: turn on port %d power\n", port));
319 	}
320 
321 	/* Wait for stable power.  Root hubs delay in their event thread. */
322         if (dev->powersrc->parent != NULL)
323 		usbd_delay_ms(dev, pwrdly);
324 
325 	/* The usual exploration will finish the setup. */
326 
327 	sc->sc_running = 1;
328 
329 	return;
330 
331  bad:
332 	if (sc->sc_statusbuf)
333 		free(sc->sc_statusbuf, M_USBDEV);
334 	if (hub) {
335 		if (hub->ports)
336 			free(hub->ports, M_USBDEV);
337 		free(hub, M_USBDEV);
338 	}
339 	dev->hub = NULL;
340 }
341 
342 usbd_status
343 uhub_explore(usbd_device_handle dev)
344 {
345 	usb_hub_descriptor_t *hd = &dev->hub->hubdesc;
346 	struct uhub_softc *sc = dev->hub->hubsoftc;
347 	struct usbd_port *up;
348 	usbd_status err;
349 	int speed;
350 	int port;
351 	int change, status, reconnect;
352 
353 	DPRINTFN(10, ("uhub_explore dev=%p addr=%d\n", dev, dev->address));
354 
355 	if (usbd_is_dying(dev)) {
356 		DPRINTF(("%s: dying\n", __func__));
357 		return (USBD_IOERROR);
358 	}
359 
360 	if (!sc->sc_running)
361 		return (USBD_NOT_STARTED);
362 
363 	/* Ignore hubs that are too deep. */
364 	if (dev->depth > USB_HUB_MAX_DEPTH)
365 		return (USBD_TOO_DEEP);
366 
367 	for (port = 1; port <= hd->bNbrPorts; port++) {
368 		up = &dev->hub->ports[port-1];
369 		err = usbd_get_port_status(dev, port, &up->status);
370 		if (err) {
371 			DPRINTF(("uhub_explore: get port status failed, "
372 				 "error=%s\n", usbd_errstr(err)));
373 			continue;
374 		}
375 		status = UGETW(up->status.wPortStatus);
376 		change = UGETW(up->status.wPortChange);
377 		reconnect = up->reattach;
378 		up->reattach = 0;
379 		DPRINTFN(3,("uhub_explore: %s port %d status 0x%04x 0x%04x\n",
380 			    sc->sc_dev.dv_xname, port, status, change));
381 		if (change & UPS_C_PORT_ENABLED) {
382 			DPRINTF(("uhub_explore: C_PORT_ENABLED\n"));
383 			usbd_clear_port_feature(dev, port, UHF_C_PORT_ENABLE);
384 			if (change & UPS_C_CONNECT_STATUS) {
385 				/* Ignore the port error if the device
386 				   vanished. */
387 			} else if (status & UPS_PORT_ENABLED) {
388 				printf("%s: illegal enable change, port %d\n",
389 				       sc->sc_dev.dv_xname, port);
390 			} else {
391 				/* Port error condition. */
392 				if (up->restartcnt) /* no message first time */
393 					printf("%s: port error, restarting "
394 					       "port %d\n",
395 					       sc->sc_dev.dv_xname, port);
396 
397 				if (up->restartcnt++ < USBD_RESTART_MAX)
398 					goto disco;
399 				else
400 					printf("%s: port error, giving up "
401 					       "port %d\n",
402 					       sc->sc_dev.dv_xname, port);
403 			}
404 		}
405 		if (!reconnect && !(change & UPS_C_CONNECT_STATUS)) {
406 			DPRINTFN(3,("uhub_explore: port=%d !C_CONNECT_"
407 				    "STATUS\n", port));
408 			/* No status change, just do recursive explore. */
409 			if (up->device != NULL && up->device->hub != NULL)
410 				up->device->hub->explore(up->device);
411 #if 0 && defined(DIAGNOSTIC)
412 			if (up->device == NULL &&
413 			    (status & UPS_CURRENT_CONNECT_STATUS))
414 				printf("%s: connected, no device\n",
415 				       sc->sc_dev.dv_xname);
416 #endif
417 			continue;
418 		}
419 
420 		/* We have a connect status change, handle it. */
421 
422 		DPRINTF(("uhub_explore: status change hub=%d port=%d\n",
423 			 dev->address, port));
424 		usbd_clear_port_feature(dev, port, UHF_C_PORT_CONNECTION);
425 		/*usbd_clear_port_feature(dev, port, UHF_C_PORT_ENABLE);*/
426 		/*
427 		 * If there is already a device on the port the change status
428 		 * must mean that is has disconnected.  Looking at the
429 		 * current connect status is not enough to figure this out
430 		 * since a new unit may have been connected before we handle
431 		 * the disconnect.
432 		 */
433 	disco:
434 		if (up->device != NULL) {
435 			/* Disconnected */
436 			DPRINTF(("uhub_explore: device addr=%d disappeared "
437 				 "on port %d\n", up->device->address, port));
438 			usb_disconnect_port(up, &sc->sc_dev);
439 			usbd_clear_port_feature(dev, port,
440 						UHF_C_PORT_CONNECTION);
441 		}
442 		if (!(status & UPS_CURRENT_CONNECT_STATUS)) {
443 			/* Nothing connected, just ignore it. */
444 			DPRINTFN(3,("uhub_explore: port=%d !CURRENT_CONNECT"
445 				    "_STATUS\n", port));
446 			continue;
447 		}
448 
449 		/* Connected */
450 
451 		if (!(status & UPS_PORT_POWER))
452 			printf("%s: strange, connected port %d has no power\n",
453 			       sc->sc_dev.dv_xname, port);
454 
455 		/* Wait for maximum device power up time. */
456 		usbd_delay_ms(dev, USB_PORT_POWERUP_DELAY);
457 
458 		/* Reset port, which implies enabling it. */
459 		if (usbd_reset_port(dev, port, &up->status)) {
460 			printf("%s: port %d reset failed\n",
461 			       sc->sc_dev.dv_xname, port);
462 			continue;
463 		}
464 		/* Get port status again, it might have changed during reset */
465 		err = usbd_get_port_status(dev, port, &up->status);
466 		if (err) {
467 			DPRINTF(("uhub_explore: get port status failed, "
468 				 "error=%s\n", usbd_errstr(err)));
469 			continue;
470 		}
471 		status = UGETW(up->status.wPortStatus);
472 		change = UGETW(up->status.wPortChange);
473 		if (!(status & UPS_CURRENT_CONNECT_STATUS)) {
474 			/* Nothing connected, just ignore it. */
475 #ifdef UHUB_DEBUG
476 			printf("%s: port %d, device disappeared after reset\n",
477 			       sc->sc_dev.dv_xname, port);
478 #endif
479 			continue;
480 		}
481 
482 		/* Figure out device speed */
483 		if (status & UPS_HIGH_SPEED)
484 			speed = USB_SPEED_HIGH;
485 		else if (status & UPS_LOW_SPEED)
486 			speed = USB_SPEED_LOW;
487 		else
488 			speed = USB_SPEED_FULL;
489 		/* Get device info and set its address. */
490 		err = usbd_new_device(&sc->sc_dev, dev->bus,
491 			  dev->depth + 1, speed, port, up);
492 		/* XXX retry a few times? */
493 		if (err) {
494 			DPRINTFN(-1,("uhub_explore: usbd_new_device failed, "
495 				     "error=%s\n", usbd_errstr(err)));
496 			/* Avoid addressing problems by disabling. */
497 			/* usbd_reset_port(dev, port, &up->status); */
498 
499 			/*
500 			 * The unit refused to accept a new address, or had
501 			 * some other serious problem.  Since we cannot leave
502 			 * at 0 we have to disable the port instead.
503 			 */
504 			printf("%s: device problem, disabling port %d\n",
505 			       sc->sc_dev.dv_xname, port);
506 			usbd_clear_port_feature(dev, port, UHF_PORT_ENABLE);
507 		} else {
508 			/* The port set up succeeded, reset error count. */
509 			up->restartcnt = 0;
510 
511 			if (up->device->hub)
512 				up->device->hub->explore(up->device);
513 		}
514 	}
515 	return (USBD_NORMAL_COMPLETION);
516 }
517 
518 int
519 uhub_activate(struct device *self, int act)
520 {
521 	struct uhub_softc *sc = (struct uhub_softc *)self;
522 	struct usbd_hub *hub = sc->sc_hub->hub;
523 	usbd_device_handle dev;
524 	int nports, port, i;
525 
526 	switch (act) {
527 	case DVACT_DEACTIVATE:
528 		if (hub == NULL) /* malfunctioning hub */
529 			break;
530 		nports = hub->hubdesc.bNbrPorts;
531 		for(port = 0; port < nports; port++) {
532 			dev = hub->ports[port].device;
533 			if (dev != NULL && dev->subdevs != NULL) {
534 				for (i = 0; dev->subdevs[i] != NULL; i++)
535 					config_deactivate(dev->subdevs[i]);
536 			}
537 		}
538 		break;
539 	}
540 	return (0);
541 }
542 
543 /*
544  * Called from process context when the hub is gone.
545  * Detach all devices on active ports.
546  */
547 int
548 uhub_detach(struct device *self, int flags)
549 {
550 	struct uhub_softc *sc = (struct uhub_softc *)self;
551 	struct usbd_hub *hub = sc->sc_hub->hub;
552 	struct usbd_port *rup;
553 	int port, nports;
554 
555 	DPRINTF(("uhub_detach: sc=%p flags=%d\n", sc, flags));
556 
557 	if (hub == NULL)		/* Must be partially working */
558 		return (0);
559 
560 	usbd_abort_pipe(sc->sc_ipipe);
561 	usbd_close_pipe(sc->sc_ipipe);
562 
563 	nports = hub->hubdesc.bNbrPorts;
564 	for(port = 0; port < nports; port++) {
565 		rup = &hub->ports[port];
566 		if (rup->device)
567 			usb_disconnect_port(rup, self);
568 	}
569 
570 	if (hub->ports[0].tt)
571 		free(hub->ports[0].tt, M_USBDEV);
572 	if (sc->sc_statusbuf)
573 		free(sc->sc_statusbuf, M_USBDEV);
574 	if (hub->ports)
575 		free(hub->ports, M_USBDEV);
576 	free(hub, M_USBDEV);
577 	sc->sc_hub->hub = NULL;
578 
579 	return (0);
580 }
581 
582 /*
583  * Hub interrupt.
584  * This an indication that some port has changed status.
585  * Notify the bus event handler thread that we need
586  * to be explored again.
587  */
588 void
589 uhub_intr(usbd_xfer_handle xfer, usbd_private_handle addr, usbd_status status)
590 {
591 	struct uhub_softc *sc = addr;
592 
593 	DPRINTFN(5,("uhub_intr: sc=%p\n", sc));
594 	if (status == USBD_STALLED)
595 		usbd_clear_endpoint_stall_async(sc->sc_ipipe);
596 	else if (status == USBD_NORMAL_COMPLETION)
597 		usb_needs_explore(sc->sc_hub, 0);
598 	else
599 		DPRINTFN(8, ("uhub_intr: unknown status, %d\n", status));
600 }
601