[PATCH] sky2: interrupt coalescing tuning

Adjust interrupt deferral values for better performance and avoid
starvation issues under stress.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

1 files changed, 11 insertions, 15 deletions

diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index af9739c1ef5f..0b82dbba16cf 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -2115,9 +2115,8 @@ static int sky2_reset(struct sky2_hw *hw)
 
         sky2_write8(hw, B0_Y2LED, LED_STAT_ON);
 
-        /* Turn on descriptor polling (every 75us) */
-        sky2_write32(hw, B28_DPT_INI, sky2_us2clk(hw, 75));
-        sky2_write8(hw, B28_DPT_CTRL, DPT_START);
+        /* Turn off descriptor polling */
+        sky2_write32(hw, B28_DPT_CTRL, DPT_STOP);
 
         /* Turn off receive timestamp */
         sky2_write8(hw, GMAC_TI_ST_CTRL, GMT_ST_STOP);
@@ -2162,8 +2161,6 @@ static int sky2_reset(struct sky2_hw *hw)
         /* Set the list last index */
         sky2_write16(hw, STAT_LAST_IDX, STATUS_RING_SIZE - 1);
 
-        sky2_write32(hw, STAT_TX_TIMER_INI, sky2_us2clk(hw, 1000));
-
         /* These status setup values are copied from SysKonnect's driver */
         if (is_ec_a1(hw)) {
                 /* WA for dev. #4.3 */
@@ -2174,21 +2171,20 @@ static int sky2_reset(struct sky2_hw *hw)
 
                 /* set Status-FIFO ISR watermark */
                 sky2_write8(hw, STAT_FIFO_ISR_WM, 0x07);        /* WA for dev. #4.18 */
-
+                sky2_write32(hw, STAT_TX_TIMER_INI, sky2_us2clk(hw, 10000));
         } else {
-                sky2_write16(hw, STAT_TX_IDX_TH, 0x000a);
-
-                /* set Status-FIFO watermark */
-                sky2_write8(hw, STAT_FIFO_WM, 0x10);
+                sky2_write16(hw, STAT_TX_IDX_TH, 10);
+                sky2_write8(hw, STAT_FIFO_WM, 16);
 
                 /* set Status-FIFO ISR watermark */
                 if (hw->chip_id == CHIP_ID_YUKON_XL && hw->chip_rev == 0)
-                        sky2_write8(hw, STAT_FIFO_ISR_WM, 0x10);
-
-                else            /* WA dev 4.109 */
-                        sky2_write8(hw, STAT_FIFO_ISR_WM, 0x04);
+                        sky2_write8(hw, STAT_FIFO_ISR_WM, 4);
+                else
+                        sky2_write8(hw, STAT_FIFO_ISR_WM, 16);
 
-                sky2_write32(hw, STAT_ISR_TIMER_INI, 0x0190);
+                sky2_write32(hw, STAT_TX_TIMER_INI, sky2_us2clk(hw, 1000));
+                sky2_write32(hw, STAT_LEV_TIMER_INI, sky2_us2clk(hw, 100));
+                sky2_write32(hw, STAT_ISR_TIMER_INI, sky2_us2clk(hw, 20));
         }
 
         /* enable status unit */