--- /sys/src/9/bcm/usbdwc.c	Tue Mar 22 00:00:00 2016
+++ /sys/src/9/bcm/usbdwc.c	Tue Mar 22 00:00:00 2016
@@ -565,6 +565,7 @@
 		}else
 			b->wp += chanio(ep, hc, Epin, DATA1, data, datalen);
 		chanio(ep, hc, Epout, DATA1, nil, 0);
+		cachedinvse(b->rp, BLEN(b));
 		n = Rsetuplen;
 	}else{
 		if(datalen > 0)