From: Elina Pasheva Date: Tue, 6 Apr 2010 14:23:07 +0000 (+0000) Subject: NET: usb: Adding URB_ZERO_PACKET flag to usbnet.c X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=b4d562e3c3553ac58c7120555c4e4aefbb090a2a;p=linux-beck.git NET: usb: Adding URB_ZERO_PACKET flag to usbnet.c This patch adds setting of the urb transfer flag URB_ZERO_PACKET before submitting an urb for drivers that have requested it (by advertising flag FLAG_SEND_ZLP). The modification is in usbnet.c function usbnet_start_xmit(). This patch only adds the zero length flag. A subsequent patch will address the buggy code we found when devices do not advertise FLAG_SEND_ZLP in which case there is a possibility of transferring packets with non-deterministic length. This patch has been tested on kernel-2.6.34-rc3. This patch has been checked against net-2.6 tree. Signed-off-by: Elina Pasheva Signed-off-by: Rory Filer Signed-off-by: David S. Miller --- diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index 17b6a62d206e..c0f64392627c 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -1068,12 +1068,15 @@ 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 (!(info->flags & FLAG_SEND_ZLP) && (length % dev->maxpacket) == 0) { - urb->transfer_buffer_length++; - if (skb_tailroom(skb)) { - skb->data[skb->len] = 0; - __skb_put(skb, 1); - } + if (length % dev->maxpacket == 0) { + if (!(info->flags & FLAG_SEND_ZLP)) { + urb->transfer_buffer_length++; + if (skb_tailroom(skb)) { + skb->data[skb->len] = 0; + __skb_put(skb, 1); + } + } else + urb->transfer_flags |= URB_ZERO_PACKET; } spin_lock_irqsave(&dev->txq.lock, flags);