Merge pull request #16 from Qyriad/fixes/usb0-ep0-zlp

firmware: fix ZLPs for USB0 EP0
greatscottgadgets · Sep 24, 2019 · 001cdcd · 001cdcd
2 parents f21543a + 595e619
commit 001cdcd
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/firmware/platform/lpc43xx/drivers/usb/usb.c b/firmware/platform/lpc43xx/drivers/usb/usb.c
@@ -840,6 +840,11 @@ void usb_endpoint_init_without_descriptor(
 {
 	bool zero_length_terminate = (transfer_type == USB_TRANSFER_TYPE_CONTROL) && !manual_zlps;
 
+	// IN EP0 needs non-automatic-ZLPs to work around a Linux spec violation.
+	if (endpoint->address == 0) {
+		zero_length_terminate = false;
+	}
+
 	usb_endpoint_flush(endpoint);
 
 	// TODO: There are more capabilities to adjust based on the endpoint