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authorBjørn Mork <bjorn@mork.no>2012-09-02 22:26:18 +0000
committerDavid S. Miller <davem@davemloft.net>2012-09-03 13:49:00 -0400
commit85e87870fa18ec9f5df98e2d3b48f3699560a570 (patch)
tree4130f26405eb5cd803b5f553faf8b4c8cb5a8548
parent4c3a5bdae293f75cdf729c6c00124e8489af2276 (diff)
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op-kernel-dev-85e87870fa18ec9f5df98e2d3b48f3699560a570.tar.gz
net: usbnet: fix softirq storm on suspend
Suspending an open usbnet device results in constant rescheduling of usbnet_bh. commit 65841fd5 "usbnet: handle remote wakeup asap" refactored the usbnet_bh code to allow sharing the urb allocate and submit code with usbnet_resume. In this process, a test for, and immediate return on, ENOLINK from rx_submit was unintentionally dropped. The rx queue will not grow if rx_submit fails, making usbnet_bh reschedule itself. This results in a softirq storm if the error is persistent. rx_submit translates the usb_submit_urb error EHOSTUNREACH into ENOLINK, so this is an expected and persistent error for a suspended device. The old code tested for this condition and avoided rescheduling. Putting this test back. Cc: <stable@vger.kernel.org> # v3.5 Cc: Ming Lei <ming.lei@canonical.com> Cc: Oliver Neukum <oneukum@suse.de> Signed-off-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/usb/usbnet.c16
1 files changed, 12 insertions, 4 deletions
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index fd4b26d..fc9f578 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1201,19 +1201,26 @@ deferred:
}
EXPORT_SYMBOL_GPL(usbnet_start_xmit);
-static void rx_alloc_submit(struct usbnet *dev, gfp_t flags)
+static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
{
struct urb *urb;
int i;
+ int ret = 0;
/* don't refill the queue all at once */
for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
urb = usb_alloc_urb(0, flags);
if (urb != NULL) {
- if (rx_submit(dev, urb, flags) == -ENOLINK)
- return;
+ ret = rx_submit(dev, urb, flags);
+ if (ret)
+ goto err;
+ } else {
+ ret = -ENOMEM;
+ goto err;
}
}
+err:
+ return ret;
}
/*-------------------------------------------------------------------------*/
@@ -1257,7 +1264,8 @@ static void usbnet_bh (unsigned long param)
int temp = dev->rxq.qlen;
if (temp < RX_QLEN(dev)) {
- rx_alloc_submit(dev, GFP_ATOMIC);
+ if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
+ return;
if (temp != dev->rxq.qlen)
netif_dbg(dev, link, dev->net,
"rxqlen %d --> %d\n",
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