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 025D9646; Wed, 6 Nov 2024 13:21:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730899272; cv=none; b=WWnwW5sCTO8l7GhSwHhNh7yZsw2TTi0vAi45hHQW5vocTvQDQ0EMIQKP0UPYoPHh4RdIOfONUw+DRx4QSGAA1/A7WPSx10WXr/Zm0+Q7b2TdXMypp8KHqrKb45kfC2s7uEHw3bVEDzXnkUY0KMuHGYRCO1iZeDuAi5bXsN55J4c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730899272; c=relaxed/simple; bh=ZVsY64GMsWmST4zqkXJSlyHegOdTxjF/574iYcHbB+o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SvPF8/8w68uqKblTUKcgGITR6rUypPIrjTRXcD0dWCaf19Y9EgpTHm6tFtvXWXOKqsQy6QqXK2oAGhlnuv4hLUH1+tnc2Zx7yyvnj3xGZG6gZNHu33/dgwD32lLq7bzy2ZROc8dvFGH4hgSo2wXB0TBL9Wqtpn915rMeIib0fkY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=sWpoZft1; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="sWpoZft1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3117DC4CECD; Wed, 6 Nov 2024 13:21:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1730899271; bh=ZVsY64GMsWmST4zqkXJSlyHegOdTxjF/574iYcHbB+o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sWpoZft1dZVWNJH8W7FWCdJ9V2xvSPYgmv52hDJaAGAFLmI91uSmaaKHDpIkEpuut 0KcCgi2HgC/EKYCzDJ6PizhvsFm/PkYR16q6wGgqU4lO1OE8+wPt+E3rp0q8OYhq3P 13p49iYOPsmAKjTRXbzwGKkAYqd7u0x+rUPyabMA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Wander Lairson Costa , Yuying Ma , Przemek Kitszel , Rafal Romanowski , Jacob Keller , Simon Horman , Paolo Abeni , Sasha Levin Subject: [PATCH 5.15 19/73] igb: Disable threaded IRQ for igb_msix_other Date: Wed, 6 Nov 2024 13:05:23 +0100 Message-ID: <20241106120300.537177578@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241106120259.955073160@linuxfoundation.org> References: <20241106120259.955073160@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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Wander Lairson Costa [ Upstream commit 338c4d3902feb5be49bfda530a72c7ab860e2c9f ] During testing of SR-IOV, Red Hat QE encountered an issue where the ip link up command intermittently fails for the igbvf interfaces when using the PREEMPT_RT variant. Investigation revealed that e1000_write_posted_mbx returns an error due to the lack of an ACK from e1000_poll_for_ack. The underlying issue arises from the fact that IRQs are threaded by default under PREEMPT_RT. While the exact hardware details are not available, it appears that the IRQ handled by igb_msix_other must be processed before e1000_poll_for_ack times out. However, e1000_write_posted_mbx is called with preemption disabled, leading to a scenario where the IRQ is serviced only after the failure of e1000_write_posted_mbx. To resolve this, we set IRQF_NO_THREAD for the affected interrupt, ensuring that the kernel handles it immediately, thereby preventing the aforementioned error. Reproducer: #!/bin/bash # echo 2 > /sys/class/net/ens14f0/device/sriov_numvfs ipaddr_vlan=3 nic_test=ens14f0 vf=${nic_test}v0 while true; do ip link set ${nic_test} mtu 1500 ip link set ${vf} mtu 1500 ip link set $vf up ip link set ${nic_test} vf 0 vlan ${ipaddr_vlan} ip addr add 172.30.${ipaddr_vlan}.1/24 dev ${vf} ip addr add 2021:db8:${ipaddr_vlan}::1/64 dev ${vf} if ! ip link show $vf | grep 'state UP'; then echo 'Error found' break fi ip link set $vf down done Signed-off-by: Wander Lairson Costa Fixes: 9d5c824399de ("igb: PCI-Express 82575 Gigabit Ethernet driver") Reported-by: Yuying Ma Reviewed-by: Przemek Kitszel Tested-by: Rafal Romanowski Signed-off-by: Jacob Keller Reviewed-by: Simon Horman Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- drivers/net/ethernet/intel/igb/igb_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index f3a433b4c7cdb..7b4d04d33154a 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -937,7 +937,7 @@ static int igb_request_msix(struct igb_adapter *adapter) int i, err = 0, vector = 0, free_vector = 0; err = request_irq(adapter->msix_entries[vector].vector, - igb_msix_other, 0, netdev->name, adapter); + igb_msix_other, IRQF_NO_THREAD, netdev->name, adapter); if (err) goto err_out; -- 2.43.0