nusb: more locking, also close dfd

sys/src/cmd/nusb/usbd/hub.c

@@ -6,6 +6,7 @@
 #include "fns.h"
 
 Hub *hubs;
+QLock hublock;
 static int nhubs;
 static int mustdump;
 static int pollms = Pollms;
@@ -676,6 +677,7 @@ work(void)
 	 * have to poll the root hub(s) in any case.
 	 */
 	for(;;){
+		qlock(&hublock);
 Again:
 		for(h = hubs; h != nil; h = h->next)
 			for(i = 1; i <= h->nport; i++)
@@ -683,6 +685,7 @@ Again:
 					/* changes in hub list; repeat */
 					goto Again;
 				}
+		qunlock(&hublock);
 		sleep(pollms);
 		if(mustdump)
 			dump();

sys/src/cmd/nusb/usbd/usbd.c

@@ -239,12 +239,16 @@ enumerate(Event **l)
 static void
 usbdopen(Req *req)
 {
+	extern QLock hublock;
+
 	if(req->fid->qid.path == Qusbevent){
+		qlock(&hublock);
 		qlock(&evlock);
 		enumerate(&req->fid->aux);
 		((Event *)req->fid->aux)->ref++;
 		((Event *)req->fid->aux)->prev--;
 		qunlock(&evlock);
+		qunlock(&hublock);
 	}
 	respond(req, nil);
 }
@@ -307,6 +311,8 @@ startdev(Port *p)
 		fprint(2, "okay what?\n");
 		return -1;
 	}
+	close(d->dfd);
+	d->dfd = -1;
 	pushevent(formatdev(d));
 	return 0;
 }