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>
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