From 4a0c081eff43a11c65dee3ad6c457f7f58bcebe0 Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Mon, 22 Sep 2014 11:54:43 -0700 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- .../net/ethernet/broadcom/genet/bcmgenet.c | 105 +++++++++--------- 1 file 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); -- 2.41.0