e1000e : Correct Rx Threshold granularity
In e1000e driver, Rx descriptor queue is used such that hardware can add only
one descriptor at a time. So the WTHRESH granularity in RXDCTL should be set
to single descriptor. This would ensure that every time controller fills a Rx
descriptor, it is flushed to host memory. Earlier this granularity was in
cache line units i.e 2 descriptors. This leads to controller always waiting
for 2 descriptors before flushing them out. But since not more than one Rx BD
is actually available , the accumulation condition never gets hit.
Signed-off-by: Ruchika Gupta <ruchika.gupta@freescale.com>
Signed-off-by: Vakul Garg <vakul@freescale.com>
Acked-by: Roy Zang <tie-fei.zang@freescale.com>
diff --git a/drivers/net/e1000.h b/drivers/net/e1000.h
index fd1d8f8..1bbae50 100644
--- a/drivers/net/e1000.h
+++ b/drivers/net/e1000.h
@@ -1551,6 +1551,7 @@
#define E1000_RXDCTL_HTHRESH 0x00003F00 /* RXDCTL Host Threshold */
#define E1000_RXDCTL_WTHRESH 0x003F0000 /* RXDCTL Writeback Threshold */
#define E1000_RXDCTL_GRAN 0x01000000 /* RXDCTL Granularity */
+#define E1000_RXDCTL_FULL_RX_DESC_WB 0x01010000 /* GRAN=1, WTHRESH=1 */
/* Transmit Descriptor Control */
#define E1000_TXDCTL_PTHRESH 0x0000003F /* TXDCTL Prefetch Threshold */