提交 87aa9f9c 编写于 作者: F Florian Fainelli 提交者: David S. Miller

net: phy: consolidate PHY reset in phy_init_hw()

There are quite a lot of drivers touching a PHY device MII_BMCR
register to reset the PHY without taking care of:

1) ensuring that BMCR_RESET is cleared after a given timeout
2) the PHY state machine resuming to the proper state and re-applying
potentially changed settings such as auto-negotiation

Introduce phy_poll_reset() which will take care of polling the MII_BMCR
for the BMCR_RESET bit to be cleared after a given timeout or return a
timeout error code.

In order to make sure the PHY is in a correct state, phy_init_hw() first
issues a software reset through MII_BMCR and then applies any fixups.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
上级 06d87cec
......@@ -255,7 +255,8 @@ Writing a PHY driver
config_init: configures PHY into a sane state after a reset.
For instance, a Davicom PHY requires descrambling disabled.
probe: Does any setup needed by the driver
probe: Allocate phy->priv, optionally refuse to bind.
PHY may not have been reset or had fixups run yet.
suspend/resume: power management
config_aneg: Changes the speed/duplex/negotiation settings
read_status: Reads the current speed/duplex/negotiation settings
......
......@@ -318,6 +318,7 @@ int phy_mii_ioctl(struct phy_device *phydev,
{
struct mii_ioctl_data *mii_data = if_mii(ifr);
u16 val = mii_data->val_in;
int ret = 0;
switch (cmd) {
case SIOCGMIIPHY:
......@@ -362,7 +363,7 @@ int phy_mii_ioctl(struct phy_device *phydev,
if (mii_data->reg_num == MII_BMCR &&
val & BMCR_RESET)
phy_init_hw(phydev);
ret = phy_init_hw(phydev);
break;
case SIOCSHWTSTAMP:
......@@ -374,7 +375,7 @@ int phy_mii_ioctl(struct phy_device *phydev,
return -EOPNOTSUPP;
}
return 0;
return ret;
}
EXPORT_SYMBOL(phy_mii_ioctl);
......
......@@ -364,7 +364,11 @@ int phy_device_register(struct phy_device *phydev)
phydev->bus->phy_map[phydev->addr] = phydev;
/* Run all of the fixups for this PHY */
phy_scan_fixups(phydev);
err = phy_init_hw(phydev);
if (err) {
pr_err("PHY %d failed to initialize\n", phydev->addr);
goto out;
}
err = device_add(&phydev->dev);
if (err) {
......@@ -497,6 +501,47 @@ void phy_disconnect(struct phy_device *phydev)
}
EXPORT_SYMBOL(phy_disconnect);
/**
* phy_poll_reset - Safely wait until a PHY reset has properly completed
* @phydev: The PHY device to poll
*
* Description: According to IEEE 802.3, Section 2, Subsection 22.2.4.1.1, as
* published in 2008, a PHY reset may take up to 0.5 seconds. The MII BMCR
* register must be polled until the BMCR_RESET bit clears.
*
* Furthermore, any attempts to write to PHY registers may have no effect
* or even generate MDIO bus errors until this is complete.
*
* Some PHYs (such as the Marvell 88E1111) don't entirely conform to the
* standard and do not fully reset after the BMCR_RESET bit is set, and may
* even *REQUIRE* a soft-reset to properly restart autonegotiation. In an
* effort to support such broken PHYs, this function is separate from the
* standard phy_init_hw() which will zero all the other bits in the BMCR
* and reapply all driver-specific and board-specific fixups.
*/
static int phy_poll_reset(struct phy_device *phydev)
{
/* Poll until the reset bit clears (50ms per retry == 0.6 sec) */
unsigned int retries = 12;
int ret;
do {
msleep(50);
ret = phy_read(phydev, MII_BMCR);
if (ret < 0)
return ret;
} while (ret & BMCR_RESET && --retries);
if (ret & BMCR_RESET)
return -ETIMEDOUT;
/*
* Some chips (smsc911x) may still need up to another 1ms after the
* BMCR_RESET bit is cleared before they are usable.
*/
msleep(1);
return 0;
}
int phy_init_hw(struct phy_device *phydev)
{
int ret;
......@@ -504,12 +549,21 @@ int phy_init_hw(struct phy_device *phydev)
if (!phydev->drv || !phydev->drv->config_init)
return 0;
ret = phy_write(phydev, MII_BMCR, BMCR_RESET);
if (ret < 0)
return ret;
ret = phy_poll_reset(phydev);
if (ret < 0)
return ret;
ret = phy_scan_fixups(phydev);
if (ret < 0)
return ret;
return phydev->drv->config_init(phydev);
}
EXPORT_SYMBOL(phy_init_hw);
/**
* phy_attach_direct - attach a network device to a given PHY device pointer
......
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