ixgbe: fix qv_lock_napi call in ixgbe_napi_disable_all

ixgbe: fix qv_lock_napi call in ixgbe_napi_disable_all

ixgbe_napi_disable_all calls napi_disable on each queue, however the busy
polling code introduced a local_bh_disable()d context around the napi_disable.
The original author did not realize that napi_disable might sleep, which would
cause a sleep while atomic BUG. In addition, on a single processor system, the
ixgbe_qv_lock_napi loop shouldn't have to mdelay. This patch adds an
ixgbe_qv_disable along with a new IXGBE_QV_STATE_DISABLED bit, which it uses to
indicate to the poll and napi routines that the q_vector has been disabled. Now
the ixgbe_napi_disable_all function will wait until all pending work has been
finished and prevent any future work from being started.

Signed-off-by: Jacob Keller <[email protected]>
Cc: Eliezer Tamir <[email protected]>
Cc: Alexander Duyck <[email protected]>
Cc: Hyong-Youb Kim <[email protected]>
Cc: Amir Vadai <[email protected]>
Cc: Dmitry Kravkov <[email protected]>
Tested-by: Phil Schmitt <[email protected]>
Signed-off-by: Jeff Kirsher <[email protected]>