[net-next-2.6 PATCH] e1000: allow option to limit number of descriptors down to 48 per ring

[Jeff Kirsher <jeffrey.t.kirsher@intel.com>]

From: Alexander Duyck <alexander.h.duyck@intel.com>

This change makes it possible to limit the number of descriptors down to 48
per ring.  The reason for this change is to address a variation on hardware
errata 10 for 82546GB in which descriptors will be lost if more than 32
descriptors are fetched and the PCI-X MRBC is 512.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Emil Tantilov <emil.s.tantilov@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---

 drivers/net/e1000/e1000.h |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/e1000/e1000.h b/drivers/net/e1000/e1000.h
index 40b62b4..65298a6 100644
--- a/drivers/net/e1000/e1000.h
+++ b/drivers/net/e1000/e1000.h
@@ -86,12 +86,12 @@ struct e1000_adapter;
 /* TX/RX descriptor defines */
 #define E1000_DEFAULT_TXD                  256
 #define E1000_MAX_TXD                      256
-#define E1000_MIN_TXD                       80
+#define E1000_MIN_TXD                       48
 #define E1000_MAX_82544_TXD               4096
 
 #define E1000_DEFAULT_RXD                  256
 #define E1000_MAX_RXD                      256
-#define E1000_MIN_RXD                       80
+#define E1000_MIN_RXD                       48
 #define E1000_MAX_82544_RXD               4096
 
 #define E1000_MIN_ITR_USECS		10 /* 100000 irq/sec */