net: dsa: bcm_sf2: reset switch prior to initialization

Our boot agent may have left the switch in an certain configuration
state, make sure we issue a software reset prior to configuring the
switch in order to ensure the HW is in a consistent state, in particular
transmit queues and internal buffers.

Fixes: 246d7f77 ("net: dsa: add Broadcom SF2 switch driver")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/bcm_sf2.c

@@ -377,6 +377,29 @@ static irqreturn_t bcm_sf2_switch_1_isr(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+static int bcm_sf2_sw_rst(struct bcm_sf2_priv *priv)
+{
+	unsigned int timeout = 1000;
+	u32 reg;
+
+	reg = core_readl(priv, CORE_WATCHDOG_CTRL);
+	reg |= SOFTWARE_RESET | EN_CHIP_RST | EN_SW_RESET;
+	core_writel(priv, reg, CORE_WATCHDOG_CTRL);
+
+	do {
+		reg = core_readl(priv, CORE_WATCHDOG_CTRL);
+		if (!(reg & SOFTWARE_RESET))
+			break;
+
+		usleep_range(1000, 2000);
+	} while (timeout-- > 0);
+
+	if (timeout == 0)
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
 static int bcm_sf2_sw_setup(struct dsa_switch *ds)
 {
 	const char *reg_names[BCM_SF2_REGS_NUM] = BCM_SF2_REGS_NAME;
@@ -410,6 +433,12 @@ static int bcm_sf2_sw_setup(struct dsa_switch *ds)
 		base++;
 	}
 
+	ret = bcm_sf2_sw_rst(priv);
+	if (ret) {
+		pr_err("unable to software reset switch: %d\n", ret);
+		goto out_unmap;
+	}
+
 	/* Disable all interrupts and request them */
 	intrl2_0_writel(priv, 0xffffffff, INTRL2_CPU_MASK_SET);
 	intrl2_0_writel(priv, 0xffffffff, INTRL2_CPU_CLEAR);
@@ -735,29 +764,6 @@ static int bcm_sf2_sw_suspend(struct dsa_switch *ds)
 	return 0;
 }
 
-static int bcm_sf2_sw_rst(struct bcm_sf2_priv *priv)
-{
-	unsigned int timeout = 1000;
-	u32 reg;
-
-	reg = core_readl(priv, CORE_WATCHDOG_CTRL);
-	reg |= SOFTWARE_RESET | EN_CHIP_RST | EN_SW_RESET;
-	core_writel(priv, reg, CORE_WATCHDOG_CTRL);
-
-	do {
-		reg = core_readl(priv, CORE_WATCHDOG_CTRL);
-		if (!(reg & SOFTWARE_RESET))
-			break;
-
-		usleep_range(1000, 2000);
-	} while (timeout-- > 0);
-
-	if (timeout == 0)
-		return -ETIMEDOUT;
-
-	return 0;
-}
-
 static int bcm_sf2_sw_resume(struct dsa_switch *ds)
 {
 	struct bcm_sf2_priv *priv = ds_to_priv(ds);