[PATCH net-next v2 4/4] net: macb: Remove dedicated IRQ handler for WoL

[Kevin Hao <haokexin@gmail.com>]

In the current implementation, the suspend/resume path frees the
existing IRQ handler and sets up a dedicated WoL IRQ handler, then
restores the original handler upon resume. This approach is not used
by any other Ethernet driver and unnecessarily complicates the
suspend/resume process. After adjusting the IRQ handler in the previous
patches, we can now handle WoL interrupts without introducing any
overhead in the TX/RX hot path. Therefore, the dedicated WoL IRQ
handler is removed.

I have verified WoL functionality on my AMD ZynqMP board using the
following steps:
  root@amd-zynqmp:~# ifconfig end0 192.168.3.3
  root@amd-zynqmp:~# ethtool -s end0 wol a
  root@amd-zynqmp:~# echo mem >/sys/power/state

Signed-off-by: Kevin Hao <haokexin@gmail.com>
---
 drivers/net/ethernet/cadence/macb_main.c | 112 ++++++++-----------------------
 1 file changed, 27 insertions(+), 85 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 98da191a2428b471ff9ac54e1f24beb3a882c546..a4961abb95ae7fa2e40e61b5a8f0da5a83572131 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -71,7 +71,8 @@ struct sifive_fu540_macb_mgmt {
 					| MACB_BIT(TXUBR))
 
 #define MACB_INT_MISC_FLAGS	(MACB_TX_ERR_FLAGS | MACB_BIT(RXUBR) | \
-				 MACB_BIT(ISR_ROVR) | MACB_BIT(HRESP))
+				 MACB_BIT(ISR_ROVR) | MACB_BIT(HRESP) | \
+				 GEM_BIT(WOL) | MACB_BIT(WOL))
 
 /* Max length of transmit frame must be a multiple of 8 bytes */
 #define MACB_TX_LEN_ALIGN	8
@@ -2025,60 +2026,30 @@ static void macb_hresp_error_task(struct work_struct *work)
 	netif_tx_start_all_queues(dev);
 }
 
-static irqreturn_t macb_wol_interrupt(int irq, void *dev_id)
+static void macb_wol_interrupt(struct macb_queue *queue, u32 status)
 {
-	struct macb_queue *queue = dev_id;
 	struct macb *bp = queue->bp;
-	u32 status;
 
-	status = queue_readl(queue, ISR);
-
-	if (unlikely(!status))
-		return IRQ_NONE;
-
-	spin_lock(&bp->lock);
-
-	if (status & MACB_BIT(WOL)) {
-		queue_writel(queue, IDR, MACB_BIT(WOL));
-		macb_writel(bp, WOL, 0);
-		netdev_vdbg(bp->dev, "MACB WoL: queue = %u, isr = 0x%08lx\n",
-			    (unsigned int)(queue - bp->queues),
-			    (unsigned long)status);
-		macb_queue_isr_clear(bp, queue, MACB_BIT(WOL));
-		pm_wakeup_event(&bp->pdev->dev, 0);
-	}
-
-	spin_unlock(&bp->lock);
-
-	return IRQ_HANDLED;
+	queue_writel(queue, IDR, MACB_BIT(WOL));
+	macb_writel(bp, WOL, 0);
+	netdev_vdbg(bp->dev, "MACB WoL: queue = %u, isr = 0x%08lx\n",
+		    (unsigned int)(queue - bp->queues),
+		    (unsigned long)status);
+	macb_queue_isr_clear(bp, queue, MACB_BIT(WOL));
+	pm_wakeup_event(&bp->pdev->dev, 0);
 }
 
-static irqreturn_t gem_wol_interrupt(int irq, void *dev_id)
+static void gem_wol_interrupt(struct macb_queue *queue, u32 status)
 {
-	struct macb_queue *queue = dev_id;
 	struct macb *bp = queue->bp;
-	u32 status;
 
-	status = queue_readl(queue, ISR);
-
-	if (unlikely(!status))
-		return IRQ_NONE;
-
-	spin_lock(&bp->lock);
-
-	if (status & GEM_BIT(WOL)) {
-		queue_writel(queue, IDR, GEM_BIT(WOL));
-		gem_writel(bp, WOL, 0);
-		netdev_vdbg(bp->dev, "GEM WoL: queue = %u, isr = 0x%08lx\n",
-			    (unsigned int)(queue - bp->queues),
-			    (unsigned long)status);
-		macb_queue_isr_clear(bp, queue, GEM_BIT(WOL));
-		pm_wakeup_event(&bp->pdev->dev, 0);
-	}
-
-	spin_unlock(&bp->lock);
-
-	return IRQ_HANDLED;
+	queue_writel(queue, IDR, GEM_BIT(WOL));
+	gem_writel(bp, WOL, 0);
+	netdev_vdbg(bp->dev, "GEM WoL: queue = %u, isr = 0x%08lx\n",
+		    (unsigned int)(queue - bp->queues),
+		    (unsigned long)status);
+	macb_queue_isr_clear(bp, queue, GEM_BIT(WOL));
+	pm_wakeup_event(&bp->pdev->dev, 0);
 }
 
 static int macb_interrupt_misc(struct macb_queue *queue, u32 status)
@@ -2132,6 +2103,14 @@ static int macb_interrupt_misc(struct macb_queue *queue, u32 status)
 		macb_queue_isr_clear(bp, queue, MACB_BIT(HRESP));
 	}
 
+	if (macb_is_gem(bp)) {
+		if (status & GEM_BIT(WOL))
+			gem_wol_interrupt(queue, status);
+	} else {
+		if (status & MACB_BIT(WOL))
+			macb_wol_interrupt(queue, status);
+	}
+
 	return 0;
 }
 
@@ -6004,7 +5983,6 @@ static int __maybe_unused macb_suspend(struct device *dev)
 	unsigned long flags;
 	u32 tmp, ifa_local;
 	unsigned int q;
-	int err;
 
 	if (!device_may_wakeup(&bp->dev->dev))
 		phy_exit(bp->phy);
@@ -6067,39 +6045,15 @@ static int __maybe_unused macb_suspend(struct device *dev)
 			/* write IP address into register */
 			tmp |= MACB_BFEXT(IP, ifa_local);
 		}
-		spin_unlock_irqrestore(&bp->lock, flags);
 
-		/* Change interrupt handler and
-		 * Enable WoL IRQ on queue 0
-		 */
-		devm_free_irq(dev, bp->queues[0].irq, bp->queues);
 		if (macb_is_gem(bp)) {
-			err = devm_request_irq(dev, bp->queues[0].irq, gem_wol_interrupt,
-					       IRQF_SHARED, netdev->name, bp->queues);
-			if (err) {
-				dev_err(dev,
-					"Unable to request IRQ %d (error %d)\n",
-					bp->queues[0].irq, err);
-				return err;
-			}
-			spin_lock_irqsave(&bp->lock, flags);
 			queue_writel(bp->queues, IER, GEM_BIT(WOL));
 			gem_writel(bp, WOL, tmp);
-			spin_unlock_irqrestore(&bp->lock, flags);
 		} else {
-			err = devm_request_irq(dev, bp->queues[0].irq, macb_wol_interrupt,
-					       IRQF_SHARED, netdev->name, bp->queues);
-			if (err) {
-				dev_err(dev,
-					"Unable to request IRQ %d (error %d)\n",
-					bp->queues[0].irq, err);
-				return err;
-			}
-			spin_lock_irqsave(&bp->lock, flags);
 			queue_writel(bp->queues, IER, MACB_BIT(WOL));
 			macb_writel(bp, WOL, tmp);
-			spin_unlock_irqrestore(&bp->lock, flags);
 		}
+		spin_unlock_irqrestore(&bp->lock, flags);
 
 		enable_irq_wake(bp->queues[0].irq);
 	}
@@ -6141,7 +6095,6 @@ static int __maybe_unused macb_resume(struct device *dev)
 	struct macb_queue *queue;
 	unsigned long flags;
 	unsigned int q;
-	int err;
 
 	if (!device_may_wakeup(&bp->dev->dev))
 		phy_init(bp->phy);
@@ -6167,17 +6120,6 @@ static int __maybe_unused macb_resume(struct device *dev)
 		macb_queue_isr_clear(bp, bp->queues, -1);
 		spin_unlock_irqrestore(&bp->lock, flags);
 
-		/* Replace interrupt handler on queue 0 */
-		devm_free_irq(dev, bp->queues[0].irq, bp->queues);
-		err = devm_request_irq(dev, bp->queues[0].irq, macb_interrupt,
-				       IRQF_SHARED, netdev->name, bp->queues);
-		if (err) {
-			dev_err(dev,
-				"Unable to request IRQ %d (error %d)\n",
-				bp->queues[0].irq, err);
-			return err;
-		}
-
 		disable_irq_wake(bp->queues[0].irq);
 
 		/* Now make sure we disable phy before moving

-- 
2.53.0