[PATCH net-next v4 03/15] net: ethernet: cortina: Drain free queue IRQ before resize

@@ -986,6 +986,8 @@ static int geth_setup_freeq(struct gemini_ethernet *geth)
 	}
 
 	kfree(geth->freeq_pages);
+	geth->freeq_pages = NULL;
+	geth->num_freeq_pages = 0;
 err_freeq:
 	dma_free_coherent(geth->dev,
 			  sizeof(*geth->freeq_ring) << geth->freeq_order,

@@ -1026,20 +1028,37 @@ static void geth_cleanup_freeq(struct gemini_ethernet *geth)
 	}
 
 	kfree(geth->freeq_pages);
+	geth->freeq_pages = NULL;
+	geth->num_freeq_pages = 0;
 
 	dma_free_coherent(geth->dev,
 			  sizeof(*geth->freeq_ring) << geth->freeq_order,
 			  geth->freeq_ring, geth->freeq_dma_base);
+	geth->freeq_ring = NULL;
+}
+
+static void geth_set_freeq_irq(struct gemini_ethernet *geth, bool enable)
+{
+	unsigned long flags;
+	u32 val;
+
+	spin_lock_irqsave(&geth->irq_lock, flags);
+	val = readl(geth->base + GLOBAL_INTERRUPT_ENABLE_4_REG);
+	if (enable)
+		val |= SWFQ_EMPTY_INT_BIT;
+	else
+		val &= ~SWFQ_EMPTY_INT_BIT;
+	writel(val, geth->base + GLOBAL_INTERRUPT_ENABLE_4_REG);
+	spin_unlock_irqrestore(&geth->irq_lock, flags);
 }
 
 /**
  * geth_resize_freeq() - resize the software queue depth
  * @port: the port requesting the change
  *
- * This gets called at least once during probe() so the device queue gets
- * "resized" from the hardware defaults. Since both ports/net devices share
- * the same hardware queue, some synchronization between the ports is
- * needed.
+ * This is called when a port is opened or its RX ring size changes. Since
+ * both ports/net devices share the same hardware queue, some synchronization
+ * between the ports is needed.
  */
 static int geth_resize_freeq(struct gemini_ethernet_port *port)
 {

@@ -1049,8 +1068,6 @@ static int geth_resize_freeq(struct gemini_ethernet_port *port)
 	struct net_device *other_netdev;
 	unsigned int new_size = 0;
 	unsigned int new_order;
-	unsigned long flags;
-	u32 en;
 	int ret;
 
 	ASSERT_RTNL();

@@ -1084,16 +1101,11 @@ static int geth_resize_freeq(struct gemini_ethernet_port *port)
 	new_order = min(15, ilog2(new_size - 1) + 1);
 	dev_dbg(geth->dev, "set shared queue to size %d order %d\n",
 		new_size, new_order);
-	if (geth->freeq_order == new_order)
+	if (geth->freeq_ring && geth->freeq_order == new_order)
 		return 0;
 
-	spin_lock_irqsave(&geth->irq_lock, flags);
-
-	/* Disable the software queue IRQs */
-	en = readl(geth->base + GLOBAL_INTERRUPT_ENABLE_4_REG);
-	en &= ~SWFQ_EMPTY_INT_BIT;
-	writel(en, geth->base + GLOBAL_INTERRUPT_ENABLE_4_REG);
-	spin_unlock_irqrestore(&geth->irq_lock, flags);
+	disable_irq(geth->port1->irq);
+	geth_set_freeq_irq(geth, false);
 
 	/* Drop the old queue */
 	if (geth->freeq_ring)

@@ -1103,14 +1115,10 @@ static int geth_resize_freeq(struct gemini_ethernet_port *port)
 	geth->freeq_order = new_order;
 	ret = geth_setup_freeq(geth);
 
-	/* Restart the interrupts - NOTE if this is the first resize
-	 * after probe(), this is where the interrupts get turned on
-	 * in the first place.
-	 */
-	spin_lock_irqsave(&geth->irq_lock, flags);
-	en |= SWFQ_EMPTY_INT_BIT;
-	writel(en, geth->base + GLOBAL_INTERRUPT_ENABLE_4_REG);
-	spin_unlock_irqrestore(&geth->irq_lock, flags);
+	/* Enable the queue interrupt only after successful setup. */
+	if (!ret)
+		geth_set_freeq_irq(geth, true);
+	enable_irq(geth->port1->irq);
 
 	return ret;
 }

@@ -2373,6 +2381,9 @@ static irqreturn_t gemini_port_irq(int irq, void *data)
 	irqreturn_t ret = IRQ_NONE;
 	u32 val, en;
 
+	if (!port->id)
+		return IRQ_NONE;
+
 	geth = port->geth;
 	spin_lock(&geth->irq_lock);
 

@@ -2470,10 +2481,6 @@ static void gemini_ethernet_init(struct gemini_ethernet *geth)
 	writel(0, geth->base + GLOBAL_HWFQ_RWPTR_REG);
 
 	geth->freeq_frag_order = DEFAULT_RX_BUF_ORDER;
-	/* This makes the queue resize on probe() so that we
-	 * set up and enable the queue IRQ. FIXME: fragile.
-	 */
-	geth->freeq_order = 1;
 	geth->initialized = true;
 }