replace uint32 in MaxPacketSize with int

usb/endpoint.go

@@ -33,7 +33,7 @@ type EndpointInfo struct {
 	// Direction defines whether the data is flowing IN or OUT from the host perspective.
 	Direction EndpointDirection
 	// MaxPacketSize is the maximum USB packet size for a single frame/microframe.
-	MaxPacketSize uint32
+	MaxPacketSize int
 	// TransferType defines the endpoint type - bulk, interrupt, isochronous.
 	TransferType TransferType
 	// PollInterval is the maximum time between transfers for interrupt and isochronous transfer,

usb/libusb.go

@@ -44,7 +44,7 @@ func (ep libusbEndpoint) endpointInfo(dev *Descriptor) EndpointInfo {
 		Number:        int(ep.bEndpointAddress & endpointNumMask),
 		Direction:     EndpointDirection((ep.bEndpointAddress & endpointDirectionMask) != 0),
 		TransferType:  TransferType(ep.bmAttributes & transferTypeMask),
-		MaxPacketSize: uint32(ep.wMaxPacketSize),
+		MaxPacketSize: int(ep.wMaxPacketSize),
 	}
 	if ei.TransferType == TransferTypeIsochronous {
 		// bits 0-10 identify the packet size, bits 11-12 are the number of additional transactions per microframe.
@@ -52,7 +52,7 @@ func (ep libusbEndpoint) endpointInfo(dev *Descriptor) EndpointInfo {
 		// regardless of alternative setting used, where different alternative settings might define different
 		// max packet sizes.
 		// See http://libusb.org/ticket/77 for more background.
-		ei.MaxPacketSize = uint32(ep.wMaxPacketSize) & 0x07ff * (uint32(ep.wMaxPacketSize)>>11&3 + 1)
+		ei.MaxPacketSize = int(ep.wMaxPacketSize) & 0x07ff * (int(ep.wMaxPacketSize)>>11&3 + 1)
 		ei.IsoSyncType = IsoSyncType(ep.bmAttributes & isoSyncTypeMask)
 		switch ep.bmAttributes & usageTypeMask {
 		case C.LIBUSB_ISO_USAGE_TYPE_DATA:

usb/transfer.go

@@ -112,14 +112,13 @@ func (t *usbTransfer) data() []byte {
 // newUSBTransfer allocates a new transfer structure for communication with a
 // given device/endpoint, with buf as the underlying transfer buffer.
 func newUSBTransfer(dev *libusbDevHandle, ei *EndpointInfo, buf []byte, timeout time.Duration) (*usbTransfer, error) {
-	var isoPackets int
-	var isoPktSize uint32
+	var isoPackets, isoPktSize int
 	if ei.TransferType == TransferTypeIsochronous {
 		isoPktSize = ei.MaxPacketSize
-		if len(buf) < int(isoPktSize) {
-			isoPktSize = uint32(len(buf))
+		if len(buf) < isoPktSize {
+			isoPktSize = len(buf)
 		}
-		isoPackets = len(buf) / int(isoPktSize)
+		isoPackets = len(buf) / isoPktSize
 		debug.Printf("New isochronous transfer - buffer length %d, using %d packets of %d bytes each", len(buf), isoPackets, isoPktSize)
 	}
 
@@ -130,7 +129,7 @@ func newUSBTransfer(dev *libusbDevHandle, ei *EndpointInfo, buf []byte, timeout
 	}
 
 	if ei.TransferType == TransferTypeIsochronous {
-		libusb.setIsoPacketLengths(xfer, isoPktSize)
+		libusb.setIsoPacketLengths(xfer, uint32(isoPktSize))
 	}
 
 	t := &usbTransfer{

usb/transfer_test.go

@@ -27,7 +27,7 @@ func TestNewTransfer(t *testing.T) {
 		desc        string
 		dir         EndpointDirection
 		tt          TransferType
-		maxPkt      uint32
+		maxPkt      int
 		buf         int
 		timeout     time.Duration
 		wantIso     int