lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

smsc95xx: fix transmission where ZLP is expected

Browse Source 
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 <steve.glendinning@smsc.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Steve Glendinning
2009-09-22 04:00:27 +00:00
committed by David S. Miller
parent 36989b9087
commit ec47562382
3 changed files with 3 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/net/usb/usbnet.c
View File

@ -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;