e1000e: Change wthresh to 1 to avoid possible Tx stalls

[firefly-linux-kernel-4.4.55.git] / drivers / net / ethernet / intel / e1000e / e1000.h

diff --git a/drivers/net/ethernet/intel/e1000e/e1000.h b/drivers/net/ethernet/intel/e1000e/e1000.h
index cb3356c9af803509efb2c58ff4f7d0667e689e1c..04668b47a1df1a65f98eef94bea619d7a0c0c71d 100644 (file)
--- a/drivers/net/ethernet/intel/e1000e/e1000.h
+++ b/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 */