From ec4756238239f1a331d9fb95bad8b281dad56855 Mon Sep 17 00:00:00 2001 From: Steve Glendinning Date: Tue, 22 Sep 2009 04:00:27 +0000 Subject: smsc95xx: fix transmission where ZLP is expected Usbnet framework assumes USB hardware doesn't handle zero length packets, but SMSC LAN95xx requires these to be sent for correct operation. This patch fixes an easily reproducible tx lockup when sending a frame that results in exactly 512 bytes in a USB transmission (e.g. a UDP frame with 458 data bytes, due to IP headers and our USB headers). It adds an extra flag to usbnet for the hardware driver to indicate that it can handle and requires the zero length packets. This patch should not affect other usbnet users, please also consider for -stable. Signed-off-by: Steve Glendinning Signed-off-by: David S. Miller --- drivers/net/usb/smsc95xx.c | 2 +- drivers/net/usb/usbnet.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c index 3aafebdbe7b..c6c922247d0 100644 --- a/drivers/net/usb/smsc95xx.c +++ b/drivers/net/usb/smsc95xx.c @@ -1227,7 +1227,7 @@ static const struct driver_info smsc95xx_info = { .rx_fixup = smsc95xx_rx_fixup, .tx_fixup = smsc95xx_tx_fixup, .status = smsc95xx_status, - .flags = FLAG_ETHER, + .flags = FLAG_ETHER | FLAG_SEND_ZLP, }; static const struct usb_device_id products[] = { diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index 24b36f79515..ca5ca5ae061 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -1049,7 +1049,7 @@ netdev_tx_t usbnet_start_xmit (struct sk_buff *skb, * NOTE: strictly conforming cdc-ether devices should expect * the ZLP here, but ignore the one-byte packet. */ - if ((length % dev->maxpacket) == 0) { + if (!(info->flags & FLAG_SEND_ZLP) && (length % dev->maxpacket) == 0) { urb->transfer_buffer_length++; if (skb_tailroom(skb)) { skb->data[skb->len] = 0; -- cgit v1.2.3