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net: systemport: fix UniMAC reset logic 

The UniMAC CMD_SW_RESET bit is not a self-clearing bit, so we need to
assert it, wait a bit and clear it manually. As a result, umac_reset()
is updated not to return any value. The previous version of the code
simply wrote 0 to the CMD register, which would make the busy-waiting
loop exit immediately, having zero effect.

By writing 0 to the CMD register, we were clearing all bits in the CMD
register, and not using the hardware reset default values which are
set on purpose.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Florian Fainelli 2014-06-26 10:06:45 -07:00 committed by David S. Miller
parent 3b140a6788
commit 412bce83ac
1 changed files with 9 additions and 24 deletions
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33
drivers/net/ethernet/broadcom/bcmsysport.c
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@ -1254,28 +1254,17 @@ static inline void umac_enable_set(struct bcm_sysport_priv *priv,
usleep_range(1000, 2000);
}
static inline int umac_reset(struct bcm_sysport_priv *priv)
static inline void umac_reset(struct bcm_sysport_priv *priv)
{
unsigned int timeout = 0;
u32 reg;
int ret = 0;
umac_writel(priv, 0, UMAC_CMD);
while (timeout++ < 1000) {
reg = umac_readl(priv, UMAC_CMD);
if (!(reg & CMD_SW_RESET))
break;
udelay(1);
}
if (timeout == 1000) {
dev_err(&priv->pdev->dev,
"timeout waiting for MAC to come out of reset\n");
ret = -ETIMEDOUT;
}
return ret;
reg = umac_readl(priv, UMAC_CMD);
reg |= CMD_SW_RESET;
umac_writel(priv, reg, UMAC_CMD);
udelay(10);
reg = umac_readl(priv, UMAC_CMD);
reg &= ~CMD_SW_RESET;
umac_writel(priv, reg, UMAC_CMD);
}
static void umac_set_hw_addr(struct bcm_sysport_priv *priv,
@ -1303,11 +1292,7 @@ static int bcm_sysport_open(struct net_device *dev)
int ret;
/* Reset UniMAC */
ret = umac_reset(priv);
if (ret) {
netdev_err(dev, "UniMAC reset failed\n");
return ret;
}
umac_reset(priv);
/* Flush TX and RX FIFOs at TOPCTRL level */
topctrl_flush(priv);