net: bcmgenet: call bcmgenet_dma_teardown in bcmgenet_fini_dma

We should not be manipulaging the DMA_CTRL registers directly by writing
0 to them to disable DMA. This is an operation that needs to be timed to
make sure the DMA engines have been properly stopped since their state
machine stops on a packet boundary, not immediately.

Make sure that tha bcmgenet_fini_dma() calls bcmgenet_dma_teardown() to
ensure a proper DMA engine state. As a result, we need to reorder the
function bodies to resolve the use dependency.

Fixes: 1c1008c793fa ("net: bcmgenet: add main driver file")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 52 insertions, 53 deletions

diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index 11a96437862d..5cc9cae21ed5 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -1744,13 +1744,63 @@ static void bcmgenet_init_multiq(struct net_device *dev)
         bcmgenet_tdma_writel(priv, reg, DMA_CTRL);
 }
 
+static int bcmgenet_dma_teardown(struct bcmgenet_priv *priv)
+{
+        int ret = 0;
+        int timeout = 0;
+        u32 reg;
+
+        /* Disable TDMA to stop add more frames in TX DMA */
+        reg = bcmgenet_tdma_readl(priv, DMA_CTRL);
+        reg &= ~DMA_EN;
+        bcmgenet_tdma_writel(priv, reg, DMA_CTRL);
+
+        /* Check TDMA status register to confirm TDMA is disabled */
+        while (timeout++ < DMA_TIMEOUT_VAL) {
+                reg = bcmgenet_tdma_readl(priv, DMA_STATUS);
+                if (reg & DMA_DISABLED)
+                        break;
+
+                udelay(1);
+        }
+
+        if (timeout == DMA_TIMEOUT_VAL) {
+                netdev_warn(priv->dev, "Timed out while disabling TX DMA\n");
+                ret = -ETIMEDOUT;
+        }
+
+        /* Wait 10ms for packet drain in both tx and rx dma */
+        usleep_range(10000, 20000);
+
+        /* Disable RDMA */
+        reg = bcmgenet_rdma_readl(priv, DMA_CTRL);
+        reg &= ~DMA_EN;
+        bcmgenet_rdma_writel(priv, reg, DMA_CTRL);
+
+        timeout = 0;
+        /* Check RDMA status register to confirm RDMA is disabled */
+        while (timeout++ < DMA_TIMEOUT_VAL) {
+                reg = bcmgenet_rdma_readl(priv, DMA_STATUS);
+                if (reg & DMA_DISABLED)
+                        break;
+
+                udelay(1);
+        }
+
+        if (timeout == DMA_TIMEOUT_VAL) {
+                netdev_warn(priv->dev, "Timed out while disabling RX DMA\n");
+                ret = -ETIMEDOUT;
+        }
+
+        return ret;
+}
+
 static void bcmgenet_fini_dma(struct bcmgenet_priv *priv)
 {
         int i;
 
         /* disable DMA */
-        bcmgenet_rdma_writel(priv, 0, DMA_CTRL);
-        bcmgenet_tdma_writel(priv, 0, DMA_CTRL);
+        bcmgenet_dma_teardown(priv);
 
         for (i = 0; i < priv->num_tx_bds; i++) {
                 if (priv->tx_cbs[i].skb != NULL) {
@@ -2109,57 +2159,6 @@ err_clk_disable:
         return ret;
 }
 
-static int bcmgenet_dma_teardown(struct bcmgenet_priv *priv)
-{
-        int ret = 0;
-        int timeout = 0;
-        u32 reg;
-
-        /* Disable TDMA to stop add more frames in TX DMA */
-        reg = bcmgenet_tdma_readl(priv, DMA_CTRL);
-        reg &= ~DMA_EN;
-        bcmgenet_tdma_writel(priv, reg, DMA_CTRL);
-
-        /* Check TDMA status register to confirm TDMA is disabled */
-        while (timeout++ < DMA_TIMEOUT_VAL) {
-                reg = bcmgenet_tdma_readl(priv, DMA_STATUS);
-                if (reg & DMA_DISABLED)
-                        break;
-
-                udelay(1);
-        }
-
-        if (timeout == DMA_TIMEOUT_VAL) {
-                netdev_warn(priv->dev, "Timed out while disabling TX DMA\n");
-                ret = -ETIMEDOUT;
-        }
-
-        /* Wait 10ms for packet drain in both tx and rx dma */
-        usleep_range(10000, 20000);
-
-        /* Disable RDMA */
-        reg = bcmgenet_rdma_readl(priv, DMA_CTRL);
-        reg &= ~DMA_EN;
-        bcmgenet_rdma_writel(priv, reg, DMA_CTRL);
-
-        timeout = 0;
-        /* Check RDMA status register to confirm RDMA is disabled */
-        while (timeout++ < DMA_TIMEOUT_VAL) {
-                reg = bcmgenet_rdma_readl(priv, DMA_STATUS);
-                if (reg & DMA_DISABLED)
-                        break;
-
-                udelay(1);
-        }
-
-        if (timeout == DMA_TIMEOUT_VAL) {
-                netdev_warn(priv->dev, "Timed out while disabling RX DMA\n");
-                ret = -ETIMEDOUT;
-        }
-
-        return ret;
-}
-
 static void bcmgenet_netif_stop(struct net_device *dev)
 {
         struct bcmgenet_priv *priv = netdev_priv(dev);