[PATCH] USB: URB_ASYNC_UNLINK flag removed from the kernel

29 July 2005, Cambridge, MA:

This afternoon Alan Stern submitted a patch to remove the URB_ASYNC_UNLINK
flag from the Linux kernel.  Mr. Stern explained, "This flag is a relic
from an earlier, less-well-designed system.  For over a year it hasn't
been used for anything other than printing warning messages."

An anonymous spokesman for the Linux kernel development community
commented, "This is exactly the sort of thing we see happening all the
time.  As the kernel evolves, support for old techniques and old code can
be jettisoned and replaced by newer, better approaches.  Proprietary
operating systems do not have the freedom or flexibility to change so
quickly."

Mr. Stern, a staff member at Harvard University's Rowland Institute who
works on Linux only as a hobby, noted that the patch (labelled as548) did
not update two files, keyspan.c and option.c, in the USB drivers' "serial"
subdirectory.  "Those files need more extensive changes," he remarked.
"They examine the status field of several URBs at times when they're not
supposed to.  That will need to be fixed before the URB_ASYNC_UNLINK flag
is removed."

Greg Kroah-Hartman, the kernel maintainer responsible for overseeing all
of Linux's USB drivers, did not respond to our inquiries or return our
calls.  His only comment was "Applied, thanks."

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

6 files changed, 0 insertions, 8 deletions

diff --git a/drivers/usb/net/catc.c b/drivers/usb/net/catc.c
index c8be912f24e..37ef365a247 100644
--- a/drivers/usb/net/catc.c
+++ b/drivers/usb/net/catc.c
@@ -383,7 +383,6 @@ static void catc_tx_done(struct urb *urb, struct pt_regs *regs)
 
 	if (urb->status == -ECONNRESET) {
 		dbg("Tx Reset.");
-		urb->transfer_flags &= ~URB_ASYNC_UNLINK;
 		urb->status = 0;
 		catc->netdev->trans_start = jiffies;
 		catc->stats.tx_errors++;
@@ -445,7 +444,6 @@ static void catc_tx_timeout(struct net_device *netdev)
 	struct catc *catc = netdev_priv(netdev);
 
 	warn("Transmit timed out.");
-	catc->tx_urb->transfer_flags |= URB_ASYNC_UNLINK;
 	usb_unlink_urb(catc->tx_urb);
 }
 
diff --git a/drivers/usb/net/kaweth.c b/drivers/usb/net/kaweth.c
index 7ffa99b9760..e04b0ce3611 100644
--- a/drivers/usb/net/kaweth.c
+++ b/drivers/usb/net/kaweth.c
@@ -787,7 +787,6 @@ static int kaweth_start_xmit(struct sk_buff *skb, struct net_device *net)
 		      kaweth_usb_transmit_complete,
 		      kaweth);
 	kaweth->end = 0;
-	kaweth->tx_urb->transfer_flags |= URB_ASYNC_UNLINK;
 
 	if((res = usb_submit_urb(kaweth->tx_urb, GFP_ATOMIC)))
 	{
diff --git a/drivers/usb/net/pegasus.c b/drivers/usb/net/pegasus.c
index fcd6d3ccef4..7484d34780f 100644
--- a/drivers/usb/net/pegasus.c
+++ b/drivers/usb/net/pegasus.c
@@ -825,7 +825,6 @@ static void pegasus_tx_timeout(struct net_device *net)
 	pegasus_t *pegasus = netdev_priv(net);
 	if (netif_msg_timer(pegasus))
 		printk(KERN_WARNING "%s: tx timeout\n", net->name);
-	pegasus->tx_urb->transfer_flags |= URB_ASYNC_UNLINK;
 	usb_unlink_urb(pegasus->tx_urb);
 	pegasus->stats.tx_errors++;
 }
diff --git a/drivers/usb/net/rtl8150.c b/drivers/usb/net/rtl8150.c
index 59ab40ebb39..c3d4e3589e3 100644
--- a/drivers/usb/net/rtl8150.c
+++ b/drivers/usb/net/rtl8150.c
@@ -653,7 +653,6 @@ static void rtl8150_tx_timeout(struct net_device *netdev)
 {
 	rtl8150_t *dev = netdev_priv(netdev);
 	warn("%s: Tx timeout.", netdev->name);
-	dev->tx_urb->transfer_flags |= URB_ASYNC_UNLINK;
 	usb_unlink_urb(dev->tx_urb);
 	dev->stats.tx_errors++;
 }
diff --git a/drivers/usb/net/usbnet.c b/drivers/usb/net/usbnet.c
index 4682696450d..3c6eef4168e 100644
--- a/drivers/usb/net/usbnet.c
+++ b/drivers/usb/net/usbnet.c
@@ -2987,7 +2987,6 @@ static void rx_submit (struct usbnet *dev, struct urb *urb, unsigned flags)
 
 	usb_fill_bulk_urb (urb, dev->udev, dev->in,
 		skb->data, size, rx_complete, skb);
-	urb->transfer_flags |= URB_ASYNC_UNLINK;
 
 	spin_lock_irqsave (&dev->rxq.lock, lockflags);
 
@@ -3561,7 +3560,6 @@ static int usbnet_start_xmit (struct sk_buff *skb, struct net_device *net)
 
 	usb_fill_bulk_urb (urb, dev->udev, dev->out,
 			skb->data, skb->len, tx_complete, skb);
-	urb->transfer_flags |= URB_ASYNC_UNLINK;
 
 	/* don't assume the hardware handles USB_ZERO_PACKET
 	 * NOTE:  strictly conforming cdc-ether devices should expect
diff --git a/drivers/usb/net/zd1201.c b/drivers/usb/net/zd1201.c
index fc013978837..c4e479ee926 100644
--- a/drivers/usb/net/zd1201.c
+++ b/drivers/usb/net/zd1201.c
@@ -847,7 +847,6 @@ static void zd1201_tx_timeout(struct net_device *dev)
 		return;
 	dev_warn(&zd->usb->dev, "%s: TX timeout, shooting down urb\n",
 	    dev->name);
-	zd->tx_urb->transfer_flags |= URB_ASYNC_UNLINK;
 	usb_unlink_urb(zd->tx_urb);
 	zd->stats.tx_errors++;
 	/* Restart the timeout to quiet the watchdog: */