[PATCH 3/4] e1000e: Calculate the desc_len based on adapter type

[Wei Yang <weiyang@linux.vnet.ibm.com>]

desc_len represents the size of descriptor in rx_ring. There are two kinds of
rx descriptors, e1000_rx_desc_packet_split(32 byte) and
e1000_rx_desc_extended(16 byte). Different adapter will use different rx
descriptors.

When allocating the dma space for this descriptor in current implementation,
the code ignore the descriptor type and take it as e1000_rx_desc_packet_split
in any case. This behavior will not effect the function, but will require
double size of dma space.

This patch will calculate the desc_len based on the adapter type.

Tested on T420, which use e1000_rx_desc_extended and works fine.

Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
---
 drivers/net/ethernet/intel/e1000e/netdev.c |    7 ++++++-
 1 files changed, 6 insertions(+), 1 deletions(-)

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index 5cb8321..a2e8a53 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -2364,7 +2364,12 @@ int e1000e_setup_rx_resources(struct e1000_ring *rx_ring)
 			goto err_pages;
 	}
 
-	desc_len = sizeof(union e1000_rx_desc_packet_split);
+	if (adapter->rx_ps_pages) {
+		/* this is a 32 byte descriptor */
+		desc_len = sizeof(union e1000_rx_desc_packet_split);
+	} else {
+		desc_len = sizeof(union e1000_rx_desc_extended);
+	}
 
 	/* Round up to nearest 4K */
 	rx_ring->size = rx_ring->count * desc_len;
-- 
1.7.5.4