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yaml --- r: 334019 b: refs/heads/master c: 8edc0e6 h: refs/heads/master i: 334017: 00f2882 334015: 5d93992 v: v3
git-mirror · Oct 11, 2012 · 39f2fb6 · 39f2fb6
1 parent 814aac7
commit 39f2fb6
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Showing 3 changed files with 5 additions and 5 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 959859d2fe88fb26e37985445817ef5234bf9a31
+refs/heads/master: 8edc0e624db3756783233e464879eb2e3b904c13
diff --git a/trunk/drivers/net/ethernet/intel/e1000e/e1000.h b/trunk/drivers/net/ethernet/intel/e1000e/e1000.h
@@ -175,13 +175,13 @@ struct e1000_info;
 /*
  * in the case of WTHRESH, it appears at least the 82571/2 hardware
  * writes back 4 descriptors when WTHRESH=5, and 3 descriptors when
- * WTHRESH=4, and since we want 64 bytes at a time written back, set
- * it to 5
+ * WTHRESH=4, so a setting of 5 gives the most efficient bus
+ * utilization but to avoid possible Tx stalls, set it to 1
  */
 #define E1000_TXDCTL_DMA_BURST_ENABLE                          \
 	(E1000_TXDCTL_GRAN | /* set descriptor granularity */  \
 	 E1000_TXDCTL_COUNT_DESC |                             \
-	 (5 << 16) | /* wthresh must be +1 more than desired */\
+	 (1 << 16) | /* wthresh must be +1 more than desired */\
 	 (1 << 8)  | /* hthresh */                             \
 	 0x1f)       /* pthresh */
 

diff --git a/trunk/drivers/net/ethernet/intel/e1000e/netdev.c b/trunk/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -2831,7 +2831,7 @@ static void e1000_configure_tx(struct e1000_adapter *adapter)
 		 * 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
+		 * wthresh = 1 ==> burst write is disabled to avoid Tx stalls
 		 * 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