shithub: riscv

Info  •  Files  •  Log  •  Branches

minor polishing of usbd

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

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

@@ -26,7 +26,10 @@

 	char *data;

 	int len;

 	Event *link;

-	int ref, prev;

+	int ref;  /* number of readers which will read this one

+                     the next time they'll read */

+	int prev; /* number of events pointing to this one with

+                     their link pointers */

 };

 static Event *evlast;

@@ -59,7 +62,7 @@

 static void

 initevent(void)

 {

-	evlast = mallocz(sizeof(Event), 1);

+	evlast = emallocz(sizeof(Event), 1);

 }

 static void

@@ -95,8 +98,6 @@

 	qlock(&evlock);

 	e = evlast;

 	ee = emallocz(sizeof(Event), 1);

-	if(ee == nil)

-		sysfatal("malloc: %r");

 	evlast = ee;

 	e->data = data;

 	e->len = strlen(data);

@@ -180,6 +181,10 @@

 		respond(req, nil);

 		break;

 	case Qusbevent:

+		if(req->fid->aux == nil){

+			respond(req, "the front fell off");

+			return;

+		}

 		readevent(req);

 		break;

 	default:

@@ -219,9 +224,7 @@

 		for(p = h->port; p < h->port + h->nport; p++){

 			if(p->dev == nil || p->dev->usb == nil || p->hub != nil)

 				continue;

-			e = mallocz(sizeof(Event), 1);

-			if(e == nil)

-				sysfatal("malloc: %r");

+			e = emallocz(sizeof(Event), 1);

 			e->data = formatdev(p->dev);

 			e->len = strlen(e->data);

 			e->prev = 1;

@@ -251,7 +254,7 @@

 {

 	Event *e, *ee;

-	if(fid->qid.path == Qusbevent){

+	if(fid->qid.path == Qusbevent && fid->aux != nil){

 		qlock(&evlock);

 		e = fid->aux;

 		if(--e->ref == 0 && e->prev == 0){