This is a note to let you know that I've just added the patch titled
net: usbnet: fix softirq storm on suspend
to the 3.5-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-usbnet-fix-softirq-storm-on-suspend.patch
and it can be found in the queue-3.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 85e87870fa18ec9f5df98e2d3b48f3699560a570 Mon Sep 17 00:00:00 2001
From: Bjørn Mork <[email protected]>
Date: Sun, 2 Sep 2012 22:26:18 +0000
Subject: net: usbnet: fix softirq storm on suspend
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From: Bjørn Mork <[email protected]>
commit 85e87870fa18ec9f5df98e2d3b48f3699560a570 upstream.
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: Ming Lei <[email protected]>
Cc: Oliver Neukum <[email protected]>
Signed-off-by: Bjørn Mork <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/net/usb/usbnet.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1204,19 +1204,26 @@ 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;
}
/*-------------------------------------------------------------------------*/
@@ -1260,7 +1267,8 @@ static void usbnet_bh (unsigned long par
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",
Patches currently in stable-queue which might be from [email protected] are
queue-3.5/net-usbnet-fix-softirq-storm-on-suspend.patch
queue-3.5/usb-option-replace-zte-k5006-z-entry-with-vendor-class-rule.patch
queue-3.5/kobject-fix-oops-with-input0-bad-kobj_uevent_env-content-in-show_uevent.patch
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