From: Robin Jarry <robin.jarry@6wind.com>
Date: Thu, 3 Mar 2016 14:27:40 +0000 (+0100)
Subject: mlx4: ensure number of Rx queues is a power of 2
X-Git-Tag: spdx-start~7319
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=bda501616c2f2f16c9d26bec472bf82d0f9ce6b7;p=dpdk.git

mlx4: ensure number of Rx queues is a power of 2

In the documentation it is specified that the hardware only supports a
number of RX queues if it is a power of 2.

Since ibv_exp_create_qp may not return an error when the number of
queues is unsupported by hardware, sanitize the value in dev_configure.

Signed-off-by: Robin Jarry <robin.jarry@6wind.com>
---

diff --git a/drivers/net/mlx4/mlx4.c b/drivers/net/mlx4/mlx4.c
index d3cea0f846..295c38bf03 100644
--- a/drivers/net/mlx4/mlx4.c
+++ b/drivers/net/mlx4/mlx4.c
@@ -733,6 +733,12 @@ dev_configure(struct rte_eth_dev *dev)
 	}
 	if (rxqs_n == priv->rxqs_n)
 		return 0;
+	if ((rxqs_n & (rxqs_n - 1)) != 0) {
+		ERROR("%p: invalid number of RX queues (%u),"
+		      " must be a power of 2",
+		      (void *)dev, rxqs_n);
+		return EINVAL;
+	}
 	INFO("%p: RX queues number update: %u -> %u",
 	     (void *)dev, priv->rxqs_n, rxqs_n);
 	/* If RSS is enabled, disable it first. */