From: Rick Lindsley ricklind@us.ibm.com
[ Upstream commit 1b18f09d31cfa7148df15a7d5c5e0e86f105f7d1 ]
During a reset, there may have been transmits in flight that are no longer valid and cannot be fulfilled. Resetting and clearing the queues is insufficient; each skb also needs to be explicitly freed so that upper levels are not left waiting for confirmation of a transmit that will never happen. If this happens frequently enough, the apparent backlog will cause TCP to begin "congestion control" unnecessarily, culminating in permanently decreased throughput.
Fixes: d7c0ef36bde03 ("ibmvnic: Free and re-allocate scrqs when tx/rx scrqs change") Tested-by: Nick Child nnac123@linux.ibm.com Reviewed-by: Brian King brking@linux.vnet.ibm.com Signed-off-by: Rick Lindsley ricklind@us.ibm.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/ibm/ibmvnic.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index 34bf6f4eef4a..bc313d85fe13 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -5022,6 +5022,15 @@ static int ibmvnic_reset_init(struct ibmvnic_adapter *adapter) release_sub_crqs(adapter, 0); rc = init_sub_crqs(adapter); } else { + /* no need to reinitialize completely, but we do + * need to clean up transmits that were in flight + * when we processed the reset. Failure to do so + * will confound the upper layer, usually TCP, by + * creating the illusion of transmits that are + * awaiting completion. + */ + clean_tx_pools(adapter); + rc = reset_sub_crq_queues(adapter); } } else {