From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 8FA066FA7 for ; Sun, 17 Sep 2023 20:11:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id ECCC1C433C7; Sun, 17 Sep 2023 20:11:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1694981476; bh=djLYwqt6oW1+/YXVrMXpuWibjRyabdbuQmkFmOMZRFY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KZ2db/9RDMr/hE2pGJG5Kqz73AodSQWsubNovTtMMHBtmVNMpbvqbfggXojHgjgRl 8Ye1ulkX70vzGeoV5zkk0p2Oct/PVVwOKyvEqNRHWs6qsGEyAe7ylAUzOXJgl8Tufe MKSjP7m8HQTsw5VY4vgGO1ZCqKmuM+ZHbdbpxHkE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jian Shen , Jijie Shao , Paolo Abeni , Sasha Levin Subject: [PATCH 6.1 129/219] net: hns3: fix tx timeout issue Date: Sun, 17 Sep 2023 21:14:16 +0200 Message-ID: <20230917191045.654628882@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230917191040.964416434@linuxfoundation.org> References: <20230917191040.964416434@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jian Shen [ Upstream commit 61a1deacc3d4fd3d57d7fda4d935f7f7503e8440 ] Currently, the driver knocks the ring doorbell before updating the ring->last_to_use in tx flow. if the hardware transmiting packet and napi poll scheduling are fast enough, it may get the old ring->last_to_use in drivers' napi poll. In this case, the driver will think the tx is not completed, and return directly without clear the flag __QUEUE_STATE_STACK_XOFF, which may cause tx timeout. Fixes: 20d06ca2679c ("net: hns3: optimize the tx clean process") Signed-off-by: Jian Shen Signed-off-by: Jijie Shao Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c index 61f833d61f583..9942b21cd6193 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c @@ -2102,8 +2102,12 @@ static void hns3_tx_doorbell(struct hns3_enet_ring *ring, int num, */ if (test_bit(HNS3_NIC_STATE_TX_PUSH_ENABLE, &priv->state) && num && !ring->pending_buf && num <= HNS3_MAX_PUSH_BD_NUM && doorbell) { + /* This smp_store_release() pairs with smp_load_aquire() in + * hns3_nic_reclaim_desc(). Ensure that the BD valid bit + * is updated. + */ + smp_store_release(&ring->last_to_use, ring->next_to_use); hns3_tx_push_bd(ring, num); - WRITE_ONCE(ring->last_to_use, ring->next_to_use); return; } @@ -2114,6 +2118,11 @@ static void hns3_tx_doorbell(struct hns3_enet_ring *ring, int num, return; } + /* This smp_store_release() pairs with smp_load_aquire() in + * hns3_nic_reclaim_desc(). Ensure that the BD valid bit is updated. + */ + smp_store_release(&ring->last_to_use, ring->next_to_use); + if (ring->tqp->mem_base) hns3_tx_mem_doorbell(ring); else @@ -2121,7 +2130,6 @@ static void hns3_tx_doorbell(struct hns3_enet_ring *ring, int num, ring->tqp->io_base + HNS3_RING_TX_RING_TAIL_REG); ring->pending_buf = 0; - WRITE_ONCE(ring->last_to_use, ring->next_to_use); } static void hns3_tsyn(struct net_device *netdev, struct sk_buff *skb, @@ -3562,9 +3570,8 @@ static void hns3_reuse_buffer(struct hns3_enet_ring *ring, int i) static bool hns3_nic_reclaim_desc(struct hns3_enet_ring *ring, int *bytes, int *pkts, int budget) { - /* pair with ring->last_to_use update in hns3_tx_doorbell(), - * smp_store_release() is not used in hns3_tx_doorbell() because - * the doorbell operation already have the needed barrier operation. + /* This smp_load_acquire() pairs with smp_store_release() in + * hns3_tx_doorbell(). */ int ltu = smp_load_acquire(&ring->last_to_use); int ntc = ring->next_to_clean; -- 2.40.1