asix: Fix tx transfer padding for full-speed USB

[ Upstream commit 2a5809499e35b53a6044fd34e72b242688b7a862 ]

The asix.c USB Ethernet driver avoids ending a tx transfer with a zero-
length packet by appending a four-byte padding to transfers whose length
is a multiple of maxpacket. However, the hard-coded 512 byte maxpacket
length is valid for high-speed USB only; full-speed USB uses 64 byte
packets.

Signed-off-by: Ingo van Lil <inguin@gmx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/net/usb/asix.c b/drivers/net/usb/asix.c
index fda4be2..a9abee8 100644 (file)
--- a/drivers/net/usb/asix.c
+++ b/drivers/net/usb/asix.c
@@ -403,7 +403,7 @@ static struct sk_buff *asix_tx_fixup(struct usbnet *dev, struct sk_buff *skb,
        u32 packet_len;
        u32 padbytes = 0xffff0000;
 
-       padlen = ((skb->len + 4) % 512) ? 0 : 4;
+       padlen = ((skb->len + 4) & (dev->maxpacket - 1)) ? 0 : 4;
 
        if ((!skb_cloned(skb)) &&
            ((headroom + tailroom) >= (4 + padlen))) {
@@ -425,7 +425,7 @@ static struct sk_buff *asix_tx_fixup(struct usbnet *dev, struct sk_buff *skb,
        cpu_to_le32s(&packet_len);
        skb_copy_to_linear_data(skb, &packet_len, sizeof(packet_len));
 
-       if ((skb->len % 512) == 0) {
+       if (padlen) {
                cpu_to_le32s(&padbytes);
                memcpy(skb_tail_pointer(skb), &padbytes, sizeof(padbytes));
                skb_put(skb, sizeof(padbytes));