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: 246d7f773c13 ("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>

1 files changed, 29 insertions, 23 deletions

diff --git a/drivers/net/dsa/bcm_sf2.c b/drivers/net/dsa/bcm_sf2.c
index 46632e8b6336..4f4c2a7888e5 100644
--- a/drivers/net/dsa/bcm_sf2.c
+++ b/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);