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From: Stephen Hemminger <shemminger@linux-foundation.org>
To: David Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Subject: [PATCH 1/6] sky2: status polling loop (post merge)
Date: Thu, 11 Oct 2007 18:29:21 -0700	[thread overview]
Message-ID: <20071011182921.1b20505c@freepuppy.rosehill> (raw)
In-Reply-To: <20071011.182358.21595252.davem@davemloft.net>

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>

--- a/drivers/net/sky2.c	2007-10-11 18:26:56.000000000 -0700
+++ b/drivers/net/sky2.c	2007-10-11 18:27:12.000000000 -0700
@@ -2245,15 +2245,13 @@ static inline void sky2_tx_done(struct n
 }
 
 /* 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_
 				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 
 	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 
 	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;
 }

  parent reply	other threads:[~2007-10-12  1:29 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-10-12  1:19 [PATCH 0/6] sky2 patches for net-2.6 Stephen Hemminger
2007-10-12  1:19 ` [PATCH 1/6] sky2: status polling loop Stephen Hemminger
2007-10-12  1:23   ` David Miller
2007-10-12  1:25     ` Stephen Hemminger
2007-10-12  1:29     ` Stephen Hemminger [this message]
2007-10-12  1:31       ` [PATCH 1/6] sky2: status polling loop (post merge) David Miller
2007-10-12  1:36         ` Stephen Hemminger
2007-10-12  1:19 ` [PATCH 2/6] sky2: ethtool register reserved area blackout Stephen Hemminger
2007-10-12  1:19 ` [PATCH 3/6] sky2: fix power settings on Yukon XL Stephen Hemminger
2007-10-12  1:19 ` [PATCH 4/6] sky2: fiber advertise bits initialization (trivial) Stephen Hemminger
2007-10-12  1:19 ` [PATCH 5/6] sky2: use netdevice stats struct Stephen Hemminger
2007-10-12  1:19 ` [PATCH 6/6] sky2: version 1.19 Stephen Hemminger

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