From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Kirsher Subject: [net-next-2.6 PATCH 10/18] igb: only support SRRCTL_DROP_EN when using multiple queues Date: Wed, 17 Feb 2010 03:03:38 -0800 Message-ID: <20100217110337.17723.80740.stgit@localhost.localdomain> References: <20100217105953.17723.36633.stgit@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, gospo@redhat.com, Nicholas Nunley , Jeff Kirsher To: davem@davemloft.net Return-path: Received: from qmta04.westchester.pa.mail.comcast.net ([76.96.62.40]:33640 "EHLO qmta04.westchester.pa.mail.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754376Ab0BQLD4 (ORCPT ); Wed, 17 Feb 2010 06:03:56 -0500 In-Reply-To: <20100217105953.17723.36633.stgit@localhost.localdomain> Sender: netdev-owner@vger.kernel.org List-ID: From: Nick Nunley 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 Signed-off-by: Jeff Kirsher --- drivers/net/igb/igb_main.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c index 4ccc7fc..b989b34 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);