e1000: allow option to limit number of descriptors down to 48 per ring

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>
This commit is contained in:
Alexander Duyck 2010-07-19 13:43:47 +00:00 committed by David S. Miller
parent 653954825d
commit b59544649d

View 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 */