[RESEND,v1,net-next,2/5] net: stmmac: make stmmac_interrupt() function more friendly to MSI

Commit Message

Voon, Weifeng March 16, 2021, 12:18 p.m. UTC

From: Ong Boon Leong <[e-mail]>

Refactor stmmac_interrupt() by introducing stmmac_common_interrupt()
so that we prepare the ISR operation to be friendly to MSI later.

Signed-off-by: Ong Boon Leong <[e-mail]>
Signed-off-by: Voon Weifeng <[e-mail]>
---
 .../net/ethernet/stmicro/stmmac/stmmac_main.c | 59 +++++++++++--------
 1 file changed, 36 insertions(+), 23 deletions(-)

Comments

Jakub Kicinski March 16, 2021, 9:21 p.m. UTC | #1

On Tue, 16 Mar 2021 20:18:20 +0800 Voon Weifeng wrote:
> +	if (unlikely(!dev)) {
> +		netdev_err(priv->dev, "%s: invalid dev pointer\n", __func__);
> +		return IRQ_NONE;
> +	}

Where did this check come from? Please avoid defensive programming 
in the kernel unless you can point out how the condition can arise
legitimately.

Patch

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 53da3c855cba..741b100c8971 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -4253,21 +4253,8 @@  static int stmmac_set_features(struct net_device *netdev,
 	return 0;
 }
 
-/**
- *  stmmac_interrupt - main ISR
- *  @irq: interrupt number.
- *  @dev_id: to pass the net device pointer (must be valid).
- *  Description: this is the main driver interrupt service routine.
- *  It can call:
- *  o DMA service routine (to manage incoming frame reception and transmission
- *    status)
- *  o Core interrupts to manage: remote wake-up, management counter, LPI
- *    interrupts.
- */
-static irqreturn_t stmmac_interrupt(int irq, void *dev_id)
+static void stmmac_common_interrupt(struct stmmac_priv *priv)
 {
-	struct net_device *dev = (struct net_device *)dev_id;
-	struct stmmac_priv *priv = netdev_priv(dev);
 	u32 rx_cnt = priv->plat->rx_queues_to_use;
 	u32 tx_cnt = priv->plat->tx_queues_to_use;
 	u32 queues_count;
@@ -4280,13 +4267,6 @@  static irqreturn_t stmmac_interrupt(int irq, void *dev_id)
 	if (priv->irq_wake)
 		pm_wakeup_event(priv->device, 0);
 
-	/* Check if adapter is up */
-	if (test_bit(STMMAC_DOWN, &priv->state))
-		return IRQ_HANDLED;
-	/* Check if a fatal error happened */
-	if (stmmac_safety_feat_interrupt(priv))
-		return IRQ_HANDLED;
-
 	/* To handle GMAC own interrupts */
 	if ((priv->plat->has_gmac) || xmac) {
 		int status = stmmac_host_irq_status(priv, priv->hw, &priv->xstats);
@@ -4317,11 +4297,44 @@  static irqreturn_t stmmac_interrupt(int irq, void *dev_id)
 		/* PCS link status */
 		if (priv->hw->pcs) {
 			if (priv->xstats.pcs_link)
-				netif_carrier_on(dev);
+				netif_carrier_on(priv->dev);
 			else
-				netif_carrier_off(dev);
+				netif_carrier_off(priv->dev);
 		}
 	}
+}
+
+/**
+ *  stmmac_interrupt - main ISR
+ *  @irq: interrupt number.
+ *  @dev_id: to pass the net device pointer.
+ *  Description: this is the main driver interrupt service routine.
+ *  It can call:
+ *  o DMA service routine (to manage incoming frame reception and transmission
+ *    status)
+ *  o Core interrupts to manage: remote wake-up, management counter, LPI
+ *    interrupts.
+ */
+static irqreturn_t stmmac_interrupt(int irq, void *dev_id)
+{
+	struct net_device *dev = (struct net_device *)dev_id;
+	struct stmmac_priv *priv = netdev_priv(dev);
+
+	if (unlikely(!dev)) {
+		netdev_err(priv->dev, "%s: invalid dev pointer\n", __func__);
+		return IRQ_NONE;
+	}
+
+	/* Check if adapter is up */
+	if (test_bit(STMMAC_DOWN, &priv->state))
+		return IRQ_HANDLED;
+
+	/* Check if a fatal error happened */
+	if (stmmac_safety_feat_interrupt(priv))
+		return IRQ_HANDLED;
+
+	/* To handle Common interrupts */
+	stmmac_common_interrupt(priv);
 
 	/* To handle DMA interrupts */
 	stmmac_dma_interrupt(priv);