Driver anchors the tx urbs and defers the urb submission if
a transmit request comes when the interface is suspended.
Anchoring urb increments the urb reference count. These
deferred urbs are later accessed by calling usb_get_from_anchor()
for submission during interface resume. usb_get_from_anchor()
unanchors the urb but urb reference count remains same.
This causes the urb reference count to remain non-zero
after usb_free_urb() gets called and urb never gets freed.
Hence call usb_put_urb() after anchoring the urb to properly
balance the reference count for these deferred urbs. Also,
unanchor these deferred urbs during disconnect, to free them
up.
Signed-off-by: Hemant Kumar <[email protected]>
---
drivers/net/usb/usbnet.c | 3 +++
1 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 1867fe2..00b7598 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1168,6 +1168,7 @@ netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
usb_anchor_urb(urb, &dev->deferred);
/* no use to process more packets */
netif_stop_queue(net);
+ usb_put_urb(urb);
spin_unlock_irqrestore(&dev->txq.lock, flags);
netdev_dbg(dev->net, "Delaying transmission for resumption\n");
goto deferred;
@@ -1317,6 +1318,8 @@ void usbnet_disconnect (struct usb_interface *intf)
cancel_work_sync(&dev->kevent);
+ usb_scuttle_anchored_urbs(&dev->deferred);
+
if (dev->driver_info->unbind)
dev->driver_info->unbind (dev, intf);
--
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
On Thursday 25 October 2012 21:17:54 Hemant Kumar wrote:
> Driver anchors the tx urbs and defers the urb submission if
> a transmit request comes when the interface is suspended.
> Anchoring urb increments the urb reference count. These
> deferred urbs are later accessed by calling usb_get_from_anchor()
> for submission during interface resume. usb_get_from_anchor()
> unanchors the urb but urb reference count remains same.
> This causes the urb reference count to remain non-zero
> after usb_free_urb() gets called and urb never gets freed.
> Hence call usb_put_urb() after anchoring the urb to properly
> balance the reference count for these deferred urbs. Also,
> unanchor these deferred urbs during disconnect, to free them
> up.
Good catch. This needs to go into stable, too.
>
> Signed-off-by: Hemant Kumar <[email protected]>
Acked-by: Oliver Neukum <[email protected]>
Regards
Oliver
From: Oliver Neukum <[email protected]>
Date: Fri, 26 Oct 2012 09:39:16 +0200
> On Thursday 25 October 2012 21:17:54 Hemant Kumar wrote:
>> Driver anchors the tx urbs and defers the urb submission if
>> a transmit request comes when the interface is suspended.
>> Anchoring urb increments the urb reference count. These
>> deferred urbs are later accessed by calling usb_get_from_anchor()
>> for submission during interface resume. usb_get_from_anchor()
>> unanchors the urb but urb reference count remains same.
>> This causes the urb reference count to remain non-zero
>> after usb_free_urb() gets called and urb never gets freed.
>> Hence call usb_put_urb() after anchoring the urb to properly
>> balance the reference count for these deferred urbs. Also,
>> unanchor these deferred urbs during disconnect, to free them
>> up.
>
> Good catch. This needs to go into stable, too.
>>
>> Signed-off-by: Hemant Kumar <[email protected]>
> Acked-by: Oliver Neukum <[email protected]>
Applied and queued up for -stable.