6 files changed, 88 insertions, 4 deletions

diff --git a/drivers/net/e1000e/82571.c b/drivers/net/e1000e/82571.c
index d3d4a57e2450..ca663f19d7df 100644
--- a/drivers/net/e1000e/82571.c
+++ b/drivers/net/e1000e/82571.c
@@ -1801,7 +1801,8 @@ struct e1000_info e1000_82571_info = {
                                   | FLAG_RESET_OVERWRITES_LAA /* errata */
                                   | FLAG_TARC_SPEED_MODE_BIT /* errata */
                                   | FLAG_APME_CHECK_PORT_B,
-        .flags2                 = FLAG2_DISABLE_ASPM_L1, /* errata 13 */
+        .flags2                 = FLAG2_DISABLE_ASPM_L1 /* errata 13 */
+                                  | FLAG2_DMA_BURST,
         .pba                    = 38,
         .max_hw_frame_size      = DEFAULT_JUMBO,
         .get_variants           = e1000_get_variants_82571,
@@ -1819,7 +1820,8 @@ struct e1000_info e1000_82572_info = {
                                   | FLAG_RX_CSUM_ENABLED
                                   | FLAG_HAS_CTRLEXT_ON_LOAD
                                   | FLAG_TARC_SPEED_MODE_BIT, /* errata */
-        .flags2                 = FLAG2_DISABLE_ASPM_L1, /* errata 13 */
+        .flags2                 = FLAG2_DISABLE_ASPM_L1 /* errata 13 */
+                                  | FLAG2_DMA_BURST,
         .pba                    = 38,
         .max_hw_frame_size      = DEFAULT_JUMBO,
         .get_variants           = e1000_get_variants_82571,
diff --git a/drivers/net/e1000e/defines.h b/drivers/net/e1000e/defines.h
index 93b3bedae8d2..d3f7a9c3f973 100644
--- a/drivers/net/e1000e/defines.h
+++ b/drivers/net/e1000e/defines.h
@@ -446,7 +446,9 @@
 
 /* Transmit Descriptor Control */
 #define E1000_TXDCTL_PTHRESH 0x0000003F /* TXDCTL Prefetch Threshold */
+#define E1000_TXDCTL_HTHRESH 0x00003F00 /* TXDCTL Host Threshold */
 #define E1000_TXDCTL_WTHRESH 0x003F0000 /* TXDCTL Writeback Threshold */
+#define E1000_TXDCTL_GRAN    0x01000000 /* TXDCTL Granularity */
 #define E1000_TXDCTL_FULL_TX_DESC_WB 0x01010000 /* GRAN=1, WTHRESH=1 */
 #define E1000_TXDCTL_MAX_TX_DESC_PREFETCH 0x0100001F /* GRAN=1, PTHRESH=31 */
 /* Enable the counting of desc. still to be processed. */
diff --git a/drivers/net/e1000e/e1000.h b/drivers/net/e1000e/e1000.h
index f9a31c82f871..5ec0af59eeab 100644
--- a/drivers/net/e1000e/e1000.h
+++ b/drivers/net/e1000e/e1000.h
@@ -153,6 +153,33 @@ struct e1000_info;
 /* Time to wait before putting the device into D3 if there's no link (in ms). */
 #define LINK_TIMEOUT            100
 
+#define DEFAULT_RDTR                    0
+#define DEFAULT_RADV                    8
+#define BURST_RDTR                      0x20
+#define BURST_RADV                      0x20
+
+/*
+ * 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
+ */
+#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 << 8)  | /* hthresh */                             \
+         0x1f)       /* pthresh */
+
+#define E1000_RXDCTL_DMA_BURST_ENABLE                          \
+        (0x01000000 | /* set descriptor granularity */         \
+         (4 << 16)  | /* set writeback threshold    */         \
+         (4 << 8)   | /* set prefetch threshold     */         \
+         0x20)        /* set hthresh                */
+
+#define E1000_TIDV_FPD (1 << 31)
+#define E1000_RDTR_FPD (1 << 31)
+
 enum e1000_boards {
         board_82571,
         board_82572,
@@ -425,6 +452,7 @@ struct e1000_info {
 #define FLAG2_DISABLE_ASPM_L1             (1 << 3)
 #define FLAG2_HAS_PHY_STATS               (1 << 4)
 #define FLAG2_HAS_EEE                     (1 << 5)
+#define FLAG2_DMA_BURST                   (1 << 6)
 
 #define E1000_RX_DESC_PS(R, i)      \
         (&(((union e1000_rx_desc_packet_split *)((R).desc))[i]))
diff --git a/drivers/net/e1000e/es2lan.c b/drivers/net/e1000e/es2lan.c
index 45aebb4a6fe1..24f8ac9cf703 100644
--- a/drivers/net/e1000e/es2lan.c
+++ b/drivers/net/e1000e/es2lan.c
@@ -1494,6 +1494,7 @@ struct e1000_info e1000_es2_info = {
                                   | FLAG_APME_CHECK_PORT_B
                                   | FLAG_DISABLE_FC_PAUSE_TIME /* errata */
                                   | FLAG_TIPG_MEDIUM_FOR_80003ESLAN,
+        .flags2                 = FLAG2_DMA_BURST,
         .pba                    = 38,
         .max_hw_frame_size      = DEFAULT_JUMBO,
         .get_variants           = e1000_get_variants_80003es2lan,
diff --git a/drivers/net/e1000e/netdev.c b/drivers/net/e1000e/netdev.c
index c69563c3ce96..1aa4228e860a 100644
--- a/drivers/net/e1000e/netdev.c
+++ b/drivers/net/e1000e/netdev.c
@@ -2650,6 +2650,26 @@ static void e1000_configure_tx(struct e1000_adapter *adapter)
         /* Tx irq moderation */
         ew32(TADV, adapter->tx_abs_int_delay);
 
+        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);
+        }
+
         /* Program the Transmit Control Register */
         tctl = er32(TCTL);
         tctl &= ~E1000_TCTL_CT;
@@ -2872,6 +2892,29 @@ static void e1000_configure_rx(struct e1000_adapter *adapter)
         e1e_flush();
         msleep(10);
 
+        if (adapter->flags2 & FLAG2_DMA_BURST) {
+                /*
+                 * set the writeback threshold (only takes effect if the RDTR
+                 * is set). set GRAN=1 and write back up to 0x4 worth, and
+                 * enable prefetching of 0x20 rx descriptors
+                 * granularity = 01
+                 * wthresh = 04,
+                 * hthresh = 04,
+                 * pthresh = 0x20
+                 */
+                ew32(RXDCTL(0), E1000_RXDCTL_DMA_BURST_ENABLE);
+                ew32(RXDCTL(1), E1000_RXDCTL_DMA_BURST_ENABLE);
+
+                /*
+                 * override the delay timers for enabling bursting, only if
+                 * the value was not set by the user via module options
+                 */
+                if (adapter->rx_int_delay == DEFAULT_RDTR)
+                        adapter->rx_int_delay = BURST_RDTR;
+                if (adapter->rx_abs_int_delay == DEFAULT_RADV)
+                        adapter->rx_abs_int_delay = BURST_RADV;
+        }
+
         /* set the Receive Delay Timer Register */
         ew32(RDTR, adapter->rx_int_delay);
 
@@ -4235,6 +4278,16 @@ link_up:
         /* Force detection of hung controller every watchdog period */
         adapter->detect_tx_hung = 1;
 
+        /* flush partial descriptors to memory before detecting tx hang */
+        if (adapter->flags2 & FLAG2_DMA_BURST) {
+                ew32(TIDV, adapter->tx_int_delay | E1000_TIDV_FPD);
+                ew32(RDTR, adapter->rx_int_delay | E1000_RDTR_FPD);
+                /*
+                 * no need to flush the writes because the timeout code does
+                 * an er32 first thing
+                 */
+        }
+
         /*
          * With 82571 controllers, LAA may be overwritten due to controller
          * reset from the other port. Set the appropriate LAA in RAR[0]
diff --git a/drivers/net/e1000e/param.c b/drivers/net/e1000e/param.c
index 34aeec13bb16..3d36911f77f3 100644
--- a/drivers/net/e1000e/param.c
+++ b/drivers/net/e1000e/param.c
@@ -91,7 +91,6 @@ E1000_PARAM(TxAbsIntDelay, "Transmit Absolute Interrupt Delay");
  * Valid Range: 0-65535
  */
 E1000_PARAM(RxIntDelay, "Receive Interrupt Delay");
-#define DEFAULT_RDTR 0
 #define MAX_RXDELAY 0xFFFF
 #define MIN_RXDELAY 0
 
@@ -101,7 +100,6 @@ E1000_PARAM(RxIntDelay, "Receive Interrupt Delay");
  * Valid Range: 0-65535
  */
 E1000_PARAM(RxAbsIntDelay, "Receive Absolute Interrupt Delay");
-#define DEFAULT_RADV 8
 #define MAX_RXABSDELAY 0xFFFF
 #define MIN_RXABSDELAY 0