4 files changed, 30 insertions(+), 29 deletions(-)

M pc/vga.c
M port/devlance.c
M port/portdat.h
M port/qlock.c

@@ 159,7 159,7 @@ vga1(void)
 	crout(Cmode, 0xe3);	/* turn off address wrap &
 				 * word mode */
 	crout(Cmsl, 0x40);	/* 1 pixel per scan line */
-	crout(Cvertend, MAXY);	/* 480 lne display */
+	crout(Cvertend, MAXY-1);	/* 480 lne display */
 	srout(Smode, 0x06);	/* extended memory,
 				 * odd/even off */
 	srout(Sclock, 0x01);	/* 8 bits/char */

@@ 241,8 241,6 @@ lancestclose(Queue *q)
 }
 
 /*
- *  assume the q is locked external to this routine
- *
  *  the ``connect'' control message specifyies the type
  */
 Proc *lanceout;

@@ 53,10 53,10 @@ struct Rendez
 
 struct QLock
 {
+	Lock	use;			/* to use object */
 	Proc	*head;			/* next process waiting for object */
 	Proc	*tail;			/* last process waiting for object */
-	Lock	use;			/* to use object */
-	Lock	queue;			/* to access list */
+	int	locked;			/* flag */
 };
 
 struct Alarm

@@ 8,34 8,38 @@
 void
 qlock(QLock *q)
 {
-	Proc *p;
+	Proc *p, *mp;
 
-	if(canlock(&q->use))
-		return;
-	lock(&q->queue);
-	if(canlock(&q->use)){
-		unlock(&q->queue);
+	lock(&q->use);
+	if(!q->locked) {
+		q->locked = 1;
+		unlock(&q->use);
 		return;
 	}
-	if(u == 0)
-		panic("qlock");
 	p = q->tail;
+	mp = u->p;
 	if(p == 0)
-		q->head = u->p;
+		q->head = mp;
 	else
-		p->qnext = u->p;
-	q->tail = u->p;
-	u->p->qnext = 0;
-	u->p->state = Queueing;
-/*	u->p->qlock = q;	/* DEBUG */
-	unlock(&q->queue);
+		p->qnext = mp;
+	q->tail = mp;
+	mp->qnext = 0;
+	mp->state = Queueing;
+	unlock(&q->use);
 	sched();
 }
 
 int
 canqlock(QLock *q)
 {
-	return canlock(&q->use);
+	lock(&q->use);
+	if(q->locked) {
+		unlock(&q->use);
+		return 0;
+	}
+	q->locked = 1;
+	unlock(&q->use);
+	return 1;
 }
 
 void


@@ 43,17 47,16 @@ qunlock(QLock *q)
 {
 	Proc *p;
 
-	lock(&q->queue);
-/*	u->p->qlock = 0; /* DEBUG */
-	if(q->head){
-		p = q->head;
+	lock(&q->use);
+	p = q->head;
+	if(p) {
 		q->head = p->qnext;
 		if(q->head == 0)
 			q->tail = 0;
-		unlock(&q->queue);
-		ready(p);
-	}else{
 		unlock(&q->use);
-		unlock(&q->queue);
+		ready(p);
+		return;
 	}
+	q->locked = 0;
+	unlock(&q->use);
 }