From: Robert Foss <robert.foss@xxxxxxxxxxxxx> From: Grant Grundler <grundler@xxxxxxxxxxxx> https://lkml.org/lkml/2014/11/11/947 Ben Hutchings is correct. IEEE 802.3 spec section "22.2.4.1.1 Reset" requires up to 500ms delay. Mitigate the "max" delay by polling the phy until BCM_RESET bit is clear. Signed-off-by: Grant Grundler <grundler@xxxxxxxxxxxx> Signed-off-by: Robert Foss <robert.foss@xxxxxxxxxxxxx> Tested-by: Robert Foss <robert.foss@xxxxxxxxxxxxx> --- drivers/net/usb/asix_devices.c | 27 ++++++++++++++++++++++++--- 1 file changed, 24 insertions(+), 3 deletions(-) diff --git a/drivers/net/usb/asix_devices.c b/drivers/net/usb/asix_devices.c index 083dc2e..dbcdda2 100644 --- a/drivers/net/usb/asix_devices.c +++ b/drivers/net/usb/asix_devices.c @@ -212,6 +212,28 @@ static const struct net_device_ops ax88172_netdev_ops = { .ndo_set_rx_mode = ax88172_set_multicast, }; +static void asix_phy_reset(struct usbnet *dev, unsigned int reset_bits) +{ + unsigned int timeout = 5000; + + asix_mdio_write(dev->net, dev->mii.phy_id, MII_BMCR, reset_bits); + + /* give phy_id a chance to process reset */ + udelay(500); + + /* See IEEE 802.3 "22.2.4.1.1 Reset": 500ms max */ + while (timeout--) { + if (asix_mdio_read(dev->net, dev->mii.phy_id, MII_BMCR) + & BMCR_RESET) + udelay(100); + else + return; + } + + netdev_err(dev->net, "BMCR_RESET timeout on phy_id %d\n", + dev->mii.phy_id); +} + static int ax88172_bind(struct usbnet *dev, struct usb_interface *intf) { int ret = 0; @@ -258,7 +280,7 @@ static int ax88172_bind(struct usbnet *dev, struct usb_interface *intf) dev->net->needed_headroom = 4; /* cf asix_tx_fixup() */ dev->net->needed_tailroom = 4; /* cf asix_tx_fixup() */ - asix_mdio_write(dev->net, dev->mii.phy_id, MII_BMCR, BMCR_RESET); + asix_phy_reset(dev, BMCR_RESET); asix_mdio_write(dev->net, dev->mii.phy_id, MII_ADVERTISE, ADVERTISE_ALL | ADVERTISE_CSMA | ADVERTISE_PAUSE_CAP); mii_nway_restart(&dev->mii); @@ -900,8 +922,7 @@ static int ax88178_reset(struct usbnet *dev) } else if (data->phymode == PHY_MODE_RTL8211CL) rtl8211cl_phy_init(dev); - asix_mdio_write(dev->net, dev->mii.phy_id, MII_BMCR, - BMCR_RESET | BMCR_ANENABLE); + asix_phy_reset(dev, BMCR_RESET | BMCR_ANENABLE); asix_mdio_write(dev->net, dev->mii.phy_id, MII_ADVERTISE, ADVERTISE_ALL | ADVERTISE_CSMA | ADVERTISE_PAUSE_CAP); asix_mdio_write(dev->net, dev->mii.phy_id, MII_CTRL1000, -- git-series 0.8.10 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
