[PATCH 4.4 44/79] smsc75xx: Add workaround for gigabit link up hardware errata.

Greg Kroah-Hartman
2018-08-23T07:59:01Z

From: Yuiko Oshino <yuiko.oshino@microchip.com>

[ Upstream commit d461e3da905332189aad546b2ad9adbe6071c7cc ]

In certain conditions, the device may not be able to link in gigabit mode. This software workaround ensures that the device will not enter the failure state.

Fixes: d0cad871703b898a442e4049c532ec39168e5b57 ("SMSC75XX USB 2.0 Gigabit Ethernet Devices")
Signed-off-by: Yuiko Oshino <yuiko.oshino@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/usb/smsc75xx.c | 62 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 62 insertions(+)

--- a/drivers/net/usb/smsc75xx.c
+++ b/drivers/net/usb/smsc75xx.c
@@ -81,6 +81,9 @@ static bool turbo_mode = true;
module_param(turbo_mode, bool, 0644);
MODULE_PARM_DESC(turbo_mode, "Enable multiple frames per Rx transaction");

+static int smsc75xx_link_ok_nopm(struct usbnet *dev);
+static int smsc75xx_phy_gig_workaround(struct usbnet *dev);
+
static int __must_check __smsc75xx_read_reg(struct usbnet *dev, u32 index,
u32 *data, int in_pm)
{
@@ -840,6 +843,9 @@ static int smsc75xx_phy_initialize(struc
return -EIO;
}

+ /* phy workaround for gig link */
+ smsc75xx_phy_gig_workaround(dev);
+
smsc75xx_mdio_write(dev->net, dev->mii.phy_id, MII_ADVERTISE,
ADVERTISE_ALL | ADVERTISE_CSMA | ADVERTISE_PAUSE_CAP |
ADVERTISE_PAUSE_ASYM);
@@ -978,6 +984,62 @@ static int smsc75xx_wait_ready(struct us
return -EIO;
}

+static int smsc75xx_phy_gig_workaround(struct usbnet *dev)
+{
+ struct mii_if_info *mii = &dev->mii;
+ int ret = 0, timeout = 0;
+ u32 buf, link_up = 0;
+
+ /* Set the phy in Gig loopback */
+ smsc75xx_mdio_write(dev->net, mii->phy_id, MII_BMCR, 0x4040);
+
+ /* Wait for the link up */
+ do {
+ link_up = smsc75xx_link_ok_nopm(dev);
+ usleep_range(10000, 20000);
+ timeout++;
+ } while ((!link_up) && (timeout < 1000));
+
+ if (timeout >= 1000) {
+ netdev_warn(dev->net, "Timeout waiting for PHY link up\n");
+ return -EIO;
+ }
+
+ /* phy reset */
+ ret = smsc75xx_read_reg(dev, PMT_CTL, &buf);
+ if (ret < 0) {
+ netdev_warn(dev->net, "Failed to read PMT_CTL: %d\n", ret);
+ return ret;
+ }
+
+ buf |= PMT_CTL_PHY_RST;
+
+ ret = smsc75xx_write_reg(dev, PMT_CTL, buf);
+ if (ret < 0) {
+ netdev_warn(dev->net, "Failed to write PMT_CTL: %d\n", ret);
+ return ret;
+ }
+
+ timeout = 0;
+ do {
+ usleep_range(10000, 20000);
+ ret = smsc75xx_read_reg(dev, PMT_CTL, &buf);
+ if (ret < 0) {
+ netdev_warn(dev->net, "Failed to read PMT_CTL: %d\n",
+ ret);
+ return ret;
+ }
+ timeout++;
+ } while ((buf & PMT_CTL_PHY_RST) && (timeout < 100));
+
+ if (timeout >= 100) {
+ netdev_warn(dev->net, "timeout waiting for PHY Reset\n");
+ return -EIO;
+ }
+
+ return 0;
+}
+
static int smsc75xx_reset(struct usbnet *dev)
{
struct smsc75xx_priv *pdata = (struct smsc75xx_priv *)(dev->data[0]);