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Message-Id: <1411412083-9370-3-git-send-email-f.fainelli@gmail.com>
Date: Mon, 22 Sep 2014 11:54:43 -0700
From: Florian Fainelli <f.fainelli@...il.com>
To: netdev@...r.kernel.org
Cc: davem@...emloft.net, Florian Fainelli <f.fainelli@...il.com>
Subject: [PATCH net 2/2 v2] 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@...il.com>
---
Changes in v2:
- properly re-order bcmgenet_dma_teardown to resolve the use dependency
drivers/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);
--
1.9.1
--
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