From: Keith Packard <keithp@keithp.com>
Date: Mon, 30 Aug 2010 11:52:00 +0000 (-0700)
Subject: altos: Windows sends USB Out packets of 0 length. Ack them.
X-Git-Tag: debian/0.7+22+g4790f78~8
X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=commitdiff_plain;h=c7ba92317ac55272acbde12416448ebd17b983a6

altos: Windows sends USB Out packets of 0 length. Ack them.

This was an untested case as no other operating system sents 0-length
out packets (they're not necessary). The correct response is to ACK
them by clearing the OUTPKT_RDY bit so that another packet can be sent.

Signed-off-by: Keith Packard <keithp@keithp.com>
---

diff --git a/src/ao_usb.c b/src/ao_usb.c
index b55130f2..b4e3f1fe 100644
--- a/src/ao_usb.c
+++ b/src/ao_usb.c
@@ -383,8 +383,11 @@ ao_usb_pollchar(void) __critical
 		if ((USBCSOL & USBCSOL_OUTPKT_RDY) == 0)
 			return AO_READ_AGAIN;
 		ao_usb_out_bytes = (USBCNTH << 8) | USBCNTL;
-		if (ao_usb_out_bytes == 0)
+		if (ao_usb_out_bytes == 0) {
+			USBINDEX = AO_USB_OUT_EP;
+			USBCSOL &= ~USBCSOL_OUTPKT_RDY;
 			return AO_READ_AGAIN;
+		}
 	}
 	--ao_usb_out_bytes;
 	c = USBFIFO[AO_USB_OUT_EP << 1];