From 87aa9f9c61ad56d505641681812e92ad976f8608 Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Fri, 6 Dec 2013 13:01:34 -0800 Subject: [PATCH] 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: Florian Fainelli Signed-off-by: David S. Miller --- Documentation/networking/phy.txt | 3 +- drivers/net/phy/phy.c | 5 +-- drivers/net/phy/phy_device.c | 56 +++++++++++++++++++++++++++++++- 3 files changed, 60 insertions(+), 4 deletions(-) diff --git a/Documentation/networking/phy.txt b/Documentation/networking/phy.txt index d5b1a3935245..ebf270719402 100644 --- a/Documentation/networking/phy.txt +++ b/Documentation/networking/phy.txt @@ -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 diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c index 5d7101b3b604..e3dd69100da8 100644 --- a/drivers/net/phy/phy.c +++ b/drivers/net/phy/phy.c @@ -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); diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index 6db36595eac9..5a619f0dcf73 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -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 -- 2.20.1