From: Alexander Duyck <alexander.h.duyck@intel.com>
Date: Fri, 11 May 2012 08:33:11 +0000 (+0000)
Subject: ixgbevf: Do not rewind the Rx ring before bumping tail
X-Git-Tag: next-20120724~65^2~90
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=18c6308971028cc02838adc711c556d992ad8bdf;p=karo-tx-linux.git

ixgbevf: Do not rewind the Rx ring before bumping tail

The driver is going back one step from its' previous location before
bumping tail. This is incorrect.  We should just be writing the value of
next_to_use into the tail register.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Tested-by: Sibai Li <sibai.li@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---

diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
index b88218c7f60f..c27ce447e04e 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
@@ -375,8 +375,6 @@ static void ixgbevf_alloc_rx_buffers(struct ixgbevf_adapter *adapter,
 no_buffers:
 	if (rx_ring->next_to_use != i) {
 		rx_ring->next_to_use = i;
-		if (i-- == 0)
-			i = (rx_ring->count - 1);
 
 		ixgbevf_release_rx_desc(&adapter->hw, rx_ring, i);
 	}
@@ -1240,9 +1238,8 @@ static void ixgbevf_configure(struct ixgbevf_adapter *adapter)
 	ixgbevf_configure_rx(adapter);
 	for (i = 0; i < adapter->num_rx_queues; i++) {
 		struct ixgbevf_ring *ring = &adapter->rx_ring[i];
-		ixgbevf_alloc_rx_buffers(adapter, ring, ring->count);
-		ring->next_to_use = ring->count - 1;
-		writel(ring->next_to_use, adapter->hw.hw_addr + ring->tail);
+		ixgbevf_alloc_rx_buffers(adapter, ring,
+					 IXGBE_DESC_UNUSED(ring));
 	}
 }