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authorGrant Grundler <grundler@chromium.org>2016-07-27 14:13:55 -0400
committerRobert Foss <robert.foss@collabora.com>2016-07-27 16:02:32 -0400
commit52bf48ce654585cee70600aabcd890ecf5f10f24 (patch)
tree97ca81dfa0b395a52ea8a8eaee2e3afba7b8a1ba
parent228342beda009b93ec0b0c33aedf54329661de79 (diff)
downloadlinux-52bf48ce654585cee70600aabcd890ecf5f10f24.tar.gz
linux-52bf48ce654585cee70600aabcd890ecf5f10f24.tar.xz
net: asix: see 802.3 spec for phy reset
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@chromium.org> Signed-off-by: Robert Foss <robert.foss@collabora.com>
-rw-r--r--drivers/net/usb/asix_devices.c27
1 files 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,