-----Original Message----- From: souradeep chakrabarti schakrabarti@linux.microsoft.com Sent: Monday, July 3, 2023 4:50 AM To: KY Srinivasan kys@microsoft.com; Haiyang Zhang haiyangz@microsoft.com; wei.liu@kernel.org; Dexuan Cui decui@microsoft.com; davem@davemloft.net; edumazet@google.com; kuba@kernel.org; pabeni@redhat.com; Long Li longli@microsoft.com; Ajay Sharma sharmaajay@microsoft.com; leon@kernel.org; cai.huoqing@linux.dev; ssengar@linux.microsoft.com; vkuznets@redhat.com; tglx@linutronix.de; linux-hyperv@vger.kernel.org; netdev@vger.kernel.org; linux-kernel@vger.kernel.org; linux-rdma@vger.kernel.org Cc: stable@vger.kernel.org; Souradeep Chakrabarti schakrabarti@microsoft.com; Souradeep Chakrabarti schakrabarti@linux.microsoft.com Subject: [PATCH V4 net] net: mana: Fix MANA VF unload when host is unresponsive
From: Souradeep Chakrabarti schakrabarti@linux.microsoft.com
When unloading the MANA driver, mana_dealloc_queues() waits for the MANA hardware to complete any inflight packets and set the pending send count to zero. But if the hardware has failed, mana_dealloc_queues() could wait forever.
Fix this by adding a timeout to the wait. Set the timeout to 120 seconds, which is a somewhat arbitrary value that is more than long enough for functional hardware to complete any sends.
Signed-off-by: Souradeep Chakrabarti schakrabarti@linux.microsoft.com
V3 -> V4:
- Fixed the commit message to describe the context.
- Removed the vf_unload_timeout, as it is not required.
drivers/net/ethernet/microsoft/mana/mana_en.c | 26 ++++++++++++++++--- 1 file changed, 23 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c index a499e460594b..d26f1da70411 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_en.c +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c @@ -2346,7 +2346,10 @@ static int mana_dealloc_queues(struct net_device *ndev) { struct mana_port_context *apc = netdev_priv(ndev); struct gdma_dev *gd = apc->ac->gdma_dev;
unsigned long timeout; struct mana_txq *txq;
struct sk_buff *skb;
struct mana_cq *cq; int i, err;
if (apc->port_is_up)
@@ -2363,15 +2366,32 @@ static int mana_dealloc_queues(struct net_device *ndev) * to false, but it doesn't matter since mana_start_xmit() drops any * new packets due to apc->port_is_up being false. *
* Drain all the in-flight TX packets
* Drain all the in-flight TX packets.* A timeout of 120 seconds for all the queues is used.* This will break the while loop when h/w is not responding.* This value of 120 has been decided here considering max* number of queues.- timeout = jiffies + 120 * HZ; for (i = 0; i < apc->num_queues; i++) { txq = &apc->tx_qp[i].txq;
while (atomic_read(&txq->pending_sends) > 0)
while (atomic_read(&txq->pending_sends) > 0 &&time_before(jiffies, timeout)) { usleep_range(1000, 2000);}}
for (i = 0; i < apc->num_queues; i++) {
txq = &apc->tx_qp[i].txq;cq = &apc->tx_qp[i].tx_cq;while (atomic_read(&txq->pending_sends)) {skb = skb_dequeue(&txq->pending_skbs);mana_unmap_skb(skb, apc);napi_consume_skb(skb, cq->budget);
This is not in NAPI context, so it should be dev_consume_skb_any()
Thanks, - Haiyang