+ if (adapter->flags2 & FLAG2_DMA_BURST) {
+ u32 txdctl = er32(TXDCTL(0));
+ txdctl &= ~(E1000_TXDCTL_PTHRESH | E1000_TXDCTL_HTHRESH |
+ E1000_TXDCTL_WTHRESH);
+ /*
+ * set up some performance related parameters to encourage the
+ * hardware to use the bus more efficiently in bursts, depends
+ * on the tx_int_delay to be enabled,
+ * wthresh = 5 ==> burst write a cacheline (64 bytes) at a time
+ * hthresh = 1 ==> prefetch when one or more available
+ * pthresh = 0x1f ==> prefetch if internal cache 31 or less
+ * BEWARE: this seems to work but should be considered first if
+ * there are tx hangs or other tx related bugs
+ */
+ txdctl |= E1000_TXDCTL_DMA_BURST_ENABLE;
+ ew32(TXDCTL(0), txdctl);
+ /* erratum work around: set txdctl the same for both queues */
+ ew32(TXDCTL(1), txdctl);
+ }
+