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Commit 4a0c081e authored by Florian Fainelli's avatar Florian Fainelli Committed by David S. Miller
Browse files

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: 1c1008c7 ("net: bcmgenet: add main driver file")
Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 478a010c

drivers/net/ethernet/broadcom/genet/bcmgenet.c

+52 −53
Original line number Diff line number Diff line
@@ -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 @@ static int bcmgenet_open(struct net_device *dev) 
	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);