[9front] [PATCH 3/5] nusb/audio: only consider data endpoints when setting up stream

[Michael Forney <mforney@mforney.org>]

An async iso endpoint has a data endpoint and feedback endpoint, and
both get mapped to the same slot in d->usb->ep. However, when setting
up audio streams, we are only interested in the data endpoints. If
the feedback endpoint appears first in the list, we end up trying to
use feedback endpoints for audio data and ignore the data endpoints.
---
 sys/src/cmd/nusb/audio/audio.c | 48 +++++++++++++++++++---------------
 sys/src/cmd/nusb/lib/usb.h     |  5 ++++
 2 files changed, 32 insertions(+), 21 deletions(-)

diff --git a/sys/src/cmd/nusb/audio/audio.c b/sys/src/cmd/nusb/audio/audio.c
index 66e77da713..09b84b8c48 100644
--- a/sys/src/cmd/nusb/audio/audio.c
+++ b/sys/src/cmd/nusb/audio/audio.c
@@ -231,30 +231,36 @@ main(int argc, char *argv[])
 		parsedescr(d->usb->ddesc[i]);
 	for(i = 0; i < nelem(d->usb->ep); i++){
 		e = d->usb->ep[i];
-		if(e != nil && e->type == Eiso && e->iface->csp == CSP(Claudio, 2, 0)){
-			switch(e->dir){
-			case Ein:
-				if(audioepin != nil)
-					continue;
-				audioepin = e;
-				break;
-			case Eout:
-				if(audioepout != nil)
-					continue;
-				audioepout = e;
+		if(e == nil || e->type != Eiso || e->iface->csp != CSP(Claudio, 2, 0))
+			continue;
+		for(; e != nil; e = e->next){
+			if((e->attrib>>4 & 3) == Edata)
 				break;
-			}
-			if((ed = setupep(audiodev, e, audiofreq)) == nil){
-				fprint(2, "setupep: %r\n");
-
-				if(e == audioepin)
-					audioepin = nil;
-				if(e == audioepout)
-					audioepout = nil;
+		}
+		if(e == nil)
+			continue;
+		switch(e->dir){
+		case Ein:
+			if(audioepin != nil)
 				continue;
-			}
-			closedev(ed);
+			audioepin = e;
+			break;
+		case Eout:
+			if(audioepout != nil)
+				continue;
+			audioepout = e;
+			break;
+		}
+		if((ed = setupep(audiodev, e, audiofreq)) == nil){
+			fprint(2, "setupep: %r\n");
+
+			if(e == audioepin)
+				audioepin = nil;
+			if(e == audioepout)
+				audioepout = nil;
+			continue;
 		}
+		closedev(ed);
 	}
 	if(audioepout == nil)
 		sysfatal("no endpoints found");
diff --git a/sys/src/cmd/nusb/lib/usb.h b/sys/src/cmd/nusb/lib/usb.h
index 6fbb7c8d50..83b6039289 100644
--- a/sys/src/cmd/nusb/lib/usb.h
+++ b/sys/src/cmd/nusb/lib/usb.h
@@ -100,6 +100,11 @@ enum {
 	Ebulk = 2,
 	Eintr = 3,
 
+	/* endpoint isousage */
+	Edata = 0,
+	Efeedback = 1,
+	Eimplicit = 2,
+
 	/* config attrib */
 	Cbuspowered = 1<<7,
 	Cselfpowered = 1<<6,
-- 
2.37.3