From: Nick Nunley <nicholasx.d.nunley@intel.com>
Date: Wed, 17 Feb 2010 01:03:38 +0000 (+0000)
Subject: igb: only support SRRCTL_DROP_EN when using multiple queues
X-Git-Tag: v2.6.34-rc1~233^2~225
X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=e6bdb6fefc590ad2fb5f79e1d1d3660afbc7c8ff;p=~shefty%2Frdma-dev.git

igb: only support SRRCTL_DROP_EN when using multiple queues

The SRRCTL.DROP_EN bit should only be set when we are supporting
multiple queues. This bit is meant to prevent head of line blocking
and is unnecessary in the single queue case.

Signed-off-by: Nicholas Nunley <nicholasx.d.nunley@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c
index 4ccc7fc70f5..b989b34a4ad 100644
--- a/drivers/net/igb/igb_main.c
+++ b/drivers/net/igb/igb_main.c
@@ -2595,6 +2595,9 @@ void igb_configure_rx_ring(struct igb_adapter *adapter,
 		         E1000_SRRCTL_BSIZEPKT_SHIFT;
 		srrctl |= E1000_SRRCTL_DESCTYPE_ADV_ONEBUF;
 	}
+	/* Only set Drop Enable if we are supporting multiple queues */
+	if (adapter->vfs_allocated_count || adapter->num_rx_queues > 1)
+		srrctl |= E1000_SRRCTL_DROP_EN;
 
 	wr32(E1000_SRRCTL(reg_idx), srrctl);