From 41639fed1b32dde4ea3d94242a89308435d341be Mon Sep 17 00:00:00 2001
From: Malli Chilakala <mallikarjuna.chilakala@intel.com>
Date: Thu, 28 Apr 2005 18:51:54 -0700
Subject: [PATCH] [PATCH] ixgb: Reset status in the Rx
Reset status in the Rx descriptor prior to handing it to the controller.
Leave three Rx descriptors unused
Signed-off-by: Mallikarjuna R Chilakala <mallikarjuna.chilakala@intel.com>
Signed-off-by: Ganesh Venkatesan <ganesh.venkatesan@intel.com>
Signed-off-by: John Ronciak <john.ronciak@intel.com>
diff -up net-drivers-2.6/drivers/net/ixgb/ixgb_main.c net-drivers-2.6/drivers/net/ixgb.new/ixgb_main.c
---
drivers/net/ixgb/ixgb_main.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ixgb/ixgb_main.c b/drivers/net/ixgb/ixgb_main.c
index da6b9d6e6db9..a6a13f6fe65b 100644
--- a/drivers/net/ixgb/ixgb_main.c
+++ b/drivers/net/ixgb/ixgb_main.c
@@ -1977,8 +1977,8 @@ ixgb_alloc_rx_buffers(struct ixgb_adapter *adapter)
num_group_tail_writes = IXGB_RX_BUFFER_WRITE;
- /* leave one descriptor unused */
- while(--cleancount > 0) {
+ /* leave three descriptors unused */
+ while(--cleancount > 2) {
rx_desc = IXGB_RX_DESC(*rx_ring, i);
skb = dev_alloc_skb(adapter->rx_buffer_len + NET_IP_ALIGN);
@@ -2005,6 +2005,10 @@ ixgb_alloc_rx_buffers(struct ixgb_adapter *adapter)
PCI_DMA_FROMDEVICE);
rx_desc->buff_addr = cpu_to_le64(buffer_info->dma);
+ /* guarantee DD bit not set now before h/w gets descriptor
+ * this is the rest of the workaround for h/w double
+ * writeback. */
+ rx_desc->status = 0;
if((i & ~(num_group_tail_writes- 1)) == i) {
/* Force memory writes to complete before letting h/w