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.
Fixes: ca9c54d2d6a5 ("net: mana: Add a driver for Microsoft Azure Network Adapter (MANA)") --- V4 -> V5: * Added fixes tag * Changed the usleep_range from static to incremental value. * Initialized timeout in the begining. --- Signed-off-by: Souradeep Chakrabarti schakrabarti@linux.microsoft.com --- drivers/net/ethernet/microsoft/mana/mana_en.c | 30 ++++++++++++++++--- 1 file changed, 26 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c index a499e460594b..56b7074db1a2 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_en.c +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c @@ -2345,9 +2345,13 @@ int mana_attach(struct net_device *ndev) static int mana_dealloc_queues(struct net_device *ndev) { struct mana_port_context *apc = netdev_priv(ndev); + unsigned long timeout = jiffies + 120 * HZ; struct gdma_dev *gd = apc->ac->gdma_dev; struct mana_txq *txq; + struct sk_buff *skb; + struct mana_cq *cq; int i, err; + u32 tsleep;
if (apc->port_is_up) return -EINVAL; @@ -2363,15 +2367,33 @@ 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. */ + for (i = 0; i < apc->num_queues; i++) { txq = &apc->tx_qp[i].txq; - - while (atomic_read(&txq->pending_sends) > 0) - usleep_range(1000, 2000); + tsleep = 1000; + while (atomic_read(&txq->pending_sends) > 0 && + time_before(jiffies, timeout)) { + usleep_range(tsleep, tsleep << 1); + tsleep <<= 1; + } }
+ 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); + dev_consume_skb_any(skb); + atomic_sub(1, &txq->pending_sends); + } + } /* We're 100% sure the queues can no longer be woken up, because * we're sure now mana_poll_tx_cq() can't be running. */
Hi,
Thanks for your patch.
FYI: kernel test robot notices the stable kernel rule is not satisfied.
Rule: 'Cc: stable@vger.kernel.org' or 'commit <sha1> upstream.' Subject: [PATCH V5 net] net: mana: Fix MANA VF unload when hardware is unresponsive Link: https://lore.kernel.org/stable/1688544973-2507-1-git-send-email-schakrabarti...
The check is based on https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
On Wed, 2023-07-05 at 01:16 -0700, Souradeep Chakrabarti wrote:
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.
Fixes: ca9c54d2d6a5 ("net: mana: Add a driver for Microsoft Azure Network Adapter (MANA)")
V4 -> V5:
- Added fixes tag
- Changed the usleep_range from static to incremental value.
- Initialized timeout in the begining.
Signed-off-by: Souradeep Chakrabarti schakrabarti@linux.microsoft.com
the changelog should come after the SoB tag, and there should be no '-- - ' separator before the SoB.
Please double-check your patch with the checkpatch script before the next submission, it should catch trivial issues as the above one.
drivers/net/ethernet/microsoft/mana/mana_en.c | 30 ++++++++++++++++--- 1 file changed, 26 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c index a499e460594b..56b7074db1a2 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_en.c +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c @@ -2345,9 +2345,13 @@ int mana_attach(struct net_device *ndev) static int mana_dealloc_queues(struct net_device *ndev) { struct mana_port_context *apc = netdev_priv(ndev);
- unsigned long timeout = jiffies + 120 * HZ; struct gdma_dev *gd = apc->ac->gdma_dev; struct mana_txq *txq;
- struct sk_buff *skb;
- struct mana_cq *cq; int i, err;
- u32 tsleep;
if (apc->port_is_up) return -EINVAL; @@ -2363,15 +2367,33 @@ 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.- for (i = 0; i < apc->num_queues; i++) { txq = &apc->tx_qp[i].txq;
while (atomic_read(&txq->pending_sends) > 0)usleep_range(1000, 2000);
tsleep = 1000;while (atomic_read(&txq->pending_sends) > 0 &&time_before(jiffies, timeout)) {usleep_range(tsleep, tsleep << 1);tsleep <<= 1;}
- for (i = 0; i < apc->num_queues; i++) {
txq = &apc->tx_qp[i].txq;cq = &apc->tx_qp[i].tx_cq;
The above variable is unused, and causes a build warning. Please remove the assignment and the variable declaration.
Thanks,
Paolo
linux-stable-mirror@lists.linaro.org
-
kernel test robot -
Paolo Abeni -
Souradeep Chakrabarti