nusb/serial: implement flushes

handle reads and writes with 9pqueue(2) so they can
be flushed and wont hang the filesystem. this also
lets us get rid of the timeouts.

ftdi is still full of braindamage that should be
rewritten, but i dont have a device to test.

1 files changed, 8 insertions, 13 deletions

diff --git a/sys/src/cmd/nusb/serial/prolific.c b/sys/src/cmd/nusb/serial/prolific.c
index a0a489111..4ada08fa9 100644
--- a/sys/src/cmd/nusb/serial/prolific.c
+++ b/sys/src/cmd/nusb/serial/prolific.c
@@ -446,12 +446,13 @@ plinit(Serialport *p)
 	plgetparam(p);
 	qunlock(ser);
 	free(buf);
-	st = emallocz(255, 1);
 	qlock(ser);
-	if(serialdebug)
+	if(serialdebug){
+		st = emallocz(255, 1);
 		serdumpst(p, st, 255);
-	dsprint(2, st);
-	free(st);
+		dsprint(2, "%s", st);
+		free(st);
+	}
 	/* p gets freed by closedev, the process has a reference */
 	incref(ser->dev);
 	proccreate(statusreader, p, 8*1024);
@@ -528,31 +529,26 @@ static int
 plreadstatus(Serialport *p)
 {
 	int nr, dfd;
-	char err[40];
+	char err[ERRMAX];
 	uchar buf[VendorReqSz];
 	Serial *ser;
 
 	ser = p->s;
 
 	qlock(ser);
-	dsprint(2, "serial: reading from interrupt\n");
 	dfd = p->epintr->dfd;
-
 	qunlock(ser);
 	nr = read(dfd, buf, sizeof buf);
 	qlock(ser);
-	snprint(err, sizeof err, "%r");
-	dsprint(2, "serial: interrupt read %d %r\n", nr);
-
+	rerrstr(err, sizeof err);
 	if(nr < 0 && strstr(err, "timed out") == nil){
-		dsprint(2, "serial: need to recover, status read %d %r\n", nr);
 		if(serialrecover(ser, nil, nil, err) < 0){
 			qunlock(ser);
 			return -1;
 		}
 	}
 	if(nr < 0)
-		dsprint(2, "serial: reading status: %r");
+		dsprint(2, "serial: reading status: %r\n");
 	else if(nr >= sizeof buf - 1){
 		p->dcd = buf[8] & DcdStatus;
 		p->dsr = buf[8] & DsrStatus;
@@ -567,7 +563,6 @@ plreadstatus(Serialport *p)
 			p->novererr++;
 	} else
 		dsprint(2, "serial: bad status read %d\n", nr);
-	dsprint(2, "serial: finished read from interrupt %d\n", nr);
 	qunlock(ser);
 	return 0;
 }