[PATCH for-4.9.y 5/5] bcm63xx_enet: do not write to random DMA channel on BCM6345

[Amit Pundir <amit.pundir@linaro.org>]

From: Jonas Gorski <jonas.gorski@gmail.com>

commit d6213c1f2ad54a964b77471690264ed685718928 upstream.

The DMA controller regs actually point to DMA channel 0, so the write to
ENETDMA_CFG_REG will actually modify a random DMA channel.

Since DMA controller registers do not exist on BCM6345, guard the write
with the usual check for dma_has_sram.

Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
---
Cherry-picked from lede tree https://git.lede-project.org/?p=source.git

 drivers/net/ethernet/broadcom/bcm63xx_enet.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/bcm63xx_enet.c b/drivers/net/ethernet/broadcom/bcm63xx_enet.c
index 3760a2be5dbc..c4078401b7de 100644
--- a/drivers/net/ethernet/broadcom/bcm63xx_enet.c
+++ b/drivers/net/ethernet/broadcom/bcm63xx_enet.c
@@ -1063,7 +1063,8 @@ static int bcm_enet_open(struct net_device *dev)
 	val = enet_readl(priv, ENET_CTL_REG);
 	val |= ENET_CTL_ENABLE_MASK;
 	enet_writel(priv, val, ENET_CTL_REG);
-	enet_dma_writel(priv, ENETDMA_CFG_EN_MASK, ENETDMA_CFG_REG);
+	if (priv->dma_has_sram)
+		enet_dma_writel(priv, ENETDMA_CFG_EN_MASK, ENETDMA_CFG_REG);
 	enet_dmac_writel(priv, priv->dma_chan_en_mask,
 			 ENETDMAC_CHANCFG, priv->rx_chan);
 
-- 
2.7.4