[SKY2]: status polling loop (post merge)

Handle the corner case where budget is exhausted correctly.
And save unnecessary read of index register.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 17 insertions, 24 deletions

diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index 4e569fa0f96c..0a3203465415 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -2245,15 +2245,13 @@ static inline void sky2_tx_done(struct net_device *dev, u16 last)
 }
 
 /* Process status response ring */
-static int sky2_status_intr(struct sky2_hw *hw, int to_do)
+static int sky2_status_intr(struct sky2_hw *hw, int to_do, u16 idx)
 {
         int work_done = 0;
         unsigned rx[2] = { 0, 0 };
-        u16 hwidx = sky2_read16(hw, STAT_PUT_IDX);
 
         rmb();
-
-        while (hw->st_idx != hwidx) {
+        do {
                 struct sky2_port *sky2;
                 struct sky2_status_le *le  = hw->st_le + hw->st_idx;
                 unsigned port = le->css & CSS_LINK_BIT;
@@ -2364,7 +2362,7 @@ static int sky2_status_intr(struct sky2_hw *hw, int to_do)
                                 printk(KERN_WARNING PFX
                                        "unknown status opcode 0x%x\n", le->opcode);
                 }
-        }
+        } while (hw->st_idx != idx);
 
         /* Fully processed status ring so clear irq */
         sky2_write32(hw, STAT_CTRL, SC_STAT_CLR_IRQ);
@@ -2607,6 +2605,7 @@ static int sky2_poll(struct napi_struct *napi, int work_limit)
         struct sky2_hw *hw = container_of(napi, struct sky2_hw, napi);
         u32 status = sky2_read32(hw, B0_Y2_SP_EISR);
         int work_done = 0;
+        u16 idx;
 
         if (unlikely(status & Y2_IS_ERROR))
                 sky2_err_intr(hw, status);
@@ -2617,29 +2616,23 @@ static int sky2_poll(struct napi_struct *napi, int work_limit)
         if (status & Y2_IS_IRQ_PHY2)
                 sky2_phy_intr(hw, 1);
 
-        for(;;) {
-                work_done += sky2_status_intr(hw, work_limit);
+        while ((idx = sky2_read16(hw, STAT_PUT_IDX)) != hw->st_idx) {
+                work_done += sky2_status_intr(hw, work_limit - work_done, idx);
 
                 if (work_done >= work_limit)
-                        break;
-
-                /* More work? */
-                if (hw->st_idx != sky2_read16(hw, STAT_PUT_IDX))
-                        continue;
-
-                /* Bug/Errata workaround?
-                 * Need to kick the TX irq moderation timer.
-                 */
-                if (sky2_read8(hw, STAT_TX_TIMER_CTRL) == TIM_START) {
-                        sky2_write8(hw, STAT_TX_TIMER_CTRL, TIM_STOP);
-                        sky2_write8(hw, STAT_TX_TIMER_CTRL, TIM_START);
-                }
-
-                napi_complete(napi);
-                sky2_read32(hw, B0_Y2_SP_LISR);
-                break;
+                        goto done;
+        }
 
+        /* Bug/Errata workaround?
+         * Need to kick the TX irq moderation timer.
+         */
+        if (sky2_read8(hw, STAT_TX_TIMER_CTRL) == TIM_START) {
+                sky2_write8(hw, STAT_TX_TIMER_CTRL, TIM_STOP);
+                sky2_write8(hw, STAT_TX_TIMER_CTRL, TIM_START);
         }
+        napi_complete(napi);
+        sky2_read32(hw, B0_Y2_SP_LISR);
+done:
 
         return work_done;
 }