e1000: allow option to limit number of descriptors down to 48 per ring
authorAlexander Duyck <alexander.h.duyck@intel.com>
Mon, 19 Jul 2010 13:43:47 +0000 (13:43 +0000)
committerDavid S. Miller <davem@davemloft.net>
Tue, 20 Jul 2010 03:23:35 +0000 (20:23 -0700)
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/e1000/e1000.h

index 40b62b406b08327ace3f83626613120be8399b54..65298a6d9af7ece5589b4f42624f7ce484d75ff4 100644 (file)
@@ -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 */