From patchwork Wed Jul 5 08:16:13 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Souradeep Chakrabarti X-Patchwork-Id: 13301829 X-Patchwork-Delegate: kuba@kernel.org Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 328AB20F6 for ; Wed, 5 Jul 2023 08:16:18 +0000 (UTC) Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 3598E1709; Wed, 5 Jul 2023 01:16:17 -0700 (PDT) Received: by linux.microsoft.com (Postfix, from userid 1099) id 6B27B20A1043; Wed, 5 Jul 2023 01:16:16 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 6B27B20A1043 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1688544976; bh=WbiYtCCkfhxy2EY5js2nXgs66lTqxblIFI1ejNxQRPc=; h=From:To:Cc:Subject:Date:From; b=scSfyhRTze3AHlBP9Vv0lBFdiZGT/u683sHmKUvnmvqpfkrSOrAsuFbTLSAJ90qyC BHwcyQavvZSqPT1fSBsXFR5DgKoz1arui0ECqrj69rN9LH7jGEZ3Ot/vuxdenE/3C1 AhjBq2JrCi/duD+KPEATi5hKhnZ1UNpnkb/f0Kx8= From: Souradeep Chakrabarti To: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, longli@microsoft.com, 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, schakrabarti@microsoft.com, Souradeep Chakrabarti Subject: [PATCH V5 net] net: mana: Fix MANA VF unload when hardware is unresponsive Date: Wed, 5 Jul 2023 01:16:13 -0700 Message-Id: <1688544973-2507-1-git-send-email-schakrabarti@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 X-Spam-Status: No, score=-19.8 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,ENV_AND_HDR_SPF_MATCH,RCVD_IN_DNSWL_MED, SPF_HELO_PASS,SPF_PASS,T_SCC_BODY_TEXT_LINE,USER_IN_DEF_DKIM_WL, USER_IN_DEF_SPF_WL autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: X-Patchwork-Delegate: kuba@kernel.org 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 --- 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. */