Mailbox interrupt handler only takecare of the PF reset notification,
for other message mbx->ops.read should not be called since it gets
chance to break the foreground VF to PF communication.
Fixes: 316f4f1adc2e ("net/igb: support VF mailbox interrupt for link up/down")
Cc: stable@dpdk.org
Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
Acked-by: Wei Dai <wei.dai@intel.com>
dd18b06a32