From: Freddy Xin <freddy@xxxxxxxxxxx>
The AX88179_178A has a hardware feature that it can insert a
2-bytes pseudo header in front of each received frame by setting
the AX_RX_CTL_IPE bit. This feature is used to let the IP header
be aligned on a doubleword-aligned address, so the rx_submit() of
usbnet.c needn't reserve NET_IP_ALIGN bytes for an SKB in the case.
This patch adds a flag of driver_info "FLAG_HW_IPALIGN" which is
used in rx_submit() of usbnet.c to determine whether reserving
NET_IP_ALIGN bytes for an SKB.
Signed-off-by: Freddy Xin <freddy@xxxxxxxxxxx>
---
drivers/net/usb/ax88179_178a.c | 8 ++++----
drivers/net/usb/usbnet.c | 5 ++++-
include/linux/usb/usbnet.h | 3 +++
3 files changed, 11 insertions(+), 5 deletions(-)
diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c
index 8e8d0fc..04a2cc9 100644
--- a/drivers/net/usb/ax88179_178a.c
+++ b/drivers/net/usb/ax88179_178a.c
@@ -1374,7 +1374,7 @@ static const struct driver_info ax88179_info = {
.link_reset = ax88179_link_reset,
.reset = ax88179_reset,
.stop = ax88179_stop,
- .flags = FLAG_ETHER | FLAG_FRAMING_AX,
+ .flags = FLAG_ETHER | FLAG_FRAMING_AX | FLAG_HW_IPALIGN,
.rx_fixup = ax88179_rx_fixup,
.tx_fixup = ax88179_tx_fixup,
};
@@ -1387,7 +1387,7 @@ static const struct driver_info ax88178a_info = {
.link_reset = ax88179_link_reset,
.reset = ax88179_reset,
.stop = ax88179_stop,
- .flags = FLAG_ETHER | FLAG_FRAMING_AX,
+ .flags = FLAG_ETHER | FLAG_FRAMING_AX | FLAG_HW_IPALIGN,
.rx_fixup = ax88179_rx_fixup,
.tx_fixup = ax88179_tx_fixup,
};
@@ -1400,7 +1400,7 @@ static const struct driver_info sitecom_info = {
.link_reset = ax88179_link_reset,
.reset = ax88179_reset,
.stop = ax88179_stop,
- .flags = FLAG_ETHER | FLAG_FRAMING_AX,
+ .flags = FLAG_ETHER | FLAG_FRAMING_AX | FLAG_HW_IPALIGN,
.rx_fixup = ax88179_rx_fixup,
.tx_fixup = ax88179_tx_fixup,
};
@@ -1413,7 +1413,7 @@ static const struct driver_info samsung_info = {
.link_reset = ax88179_link_reset,
.reset = ax88179_reset,
.stop = ax88179_stop,
- .flags = FLAG_ETHER | FLAG_FRAMING_AX,
+ .flags = FLAG_ETHER | FLAG_FRAMING_AX | FLAG_HW_IPALIGN,
.rx_fixup = ax88179_rx_fixup,
.tx_fixup = ax88179_tx_fixup,
};
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 8494bb5..8a618b8 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -473,7 +473,10 @@ static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
return -ENOLINK;
}
- skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
+ if (dev->driver_info->flags & FLAG_HW_IPALIGN)
+ skb = __netdev_alloc_skb(dev->net, size, flags);
+ else
+ skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
if (!skb) {
netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
diff --git a/include/linux/usb/usbnet.h b/include/linux/usb/usbnet.h
index e303eef..e4855cf 100644
--- a/include/linux/usb/usbnet.h
+++ b/include/linux/usb/usbnet.h
@@ -116,6 +116,9 @@ struct driver_info {
#define FLAG_MULTI_PACKET 0x2000
#define FLAG_RX_ASSEMBLE 0x4000 /* rx packets may span >1 frames */
#define FLAG_NOARP 0x8000 /* device can't do ARP */
+#define FLAG_HW_IPALIGN 0x10000 /* hardware adds headers to let the
+ * IP header align on a dword-aligned
+ * address */
/* init device ... can sleep, or cause probe() failure */
int (*bind)(struct usbnet *, struct usb_interface *);
--
1.8.3.2
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