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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Sunil Goutham <sgoutham@cavium.com>,
        cjacob <cjacob@caviumnetworks.com>,
        Aleksey Makarov <aleksey.makarov@cavium.com>,
        "David S. Miller" <davem@davemloft.net>,
        Sasha Levin <alexander.levin@microsoft.com>
Subject: [PATCH 4.9 176/241] net: thunderx: Set max queue count taking XDP_TX into account
Date:   Mon, 19 Mar 2018 19:07:21 +0100
Message-Id: <20180319180758.436839994@linuxfoundation.org>
In-Reply-To: <20180319180751.172155436@linuxfoundation.org>
References: <20180319180751.172155436@linuxfoundation.org>
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4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Sunil Goutham <sgoutham@cavium.com>


[ Upstream commit 87de083857aa269fb171ef0b39696b2888361c58 ]

on T81 there are only 4 cores, hence setting max queue count to 4
would leave nothing for XDP_TX. This patch fixes this by doubling
max queue count in above scenarios.

Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: cjacob <cjacob@caviumnetworks.com>
Signed-off-by: Aleksey Makarov <aleksey.makarov@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/ethernet/cavium/thunder/nicvf_main.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
+++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
@@ -1576,6 +1576,11 @@ static int nicvf_probe(struct pci_dev *p
 	nic->pdev = pdev;
 	nic->pnicvf = nic;
 	nic->max_queues = qcount;
+	/* If no of CPUs are too low, there won't be any queues left
+	 * for XDP_TX, hence double it.
+	 */
+	if (!nic->t88)
+		nic->max_queues *= 2;
 
 	/* MAP VF's configuration registers */
 	nic->reg_base = pcim_iomap(pdev, PCI_CFG_REG_BAR_NUM, 0);