releases/4.14.67/smsc75xx-add-workaround-for-gigabit-link-up-hardware-errata.patch

   1 From foo@baz Wed Aug 22 09:33:46 CEST 2018
   2 From: Yuiko Oshino <yuiko.oshino@microchip.com>
   3 Date: Tue, 3 Jul 2018 11:21:46 -0400
   4 Subject: smsc75xx: Add workaround for gigabit link up hardware errata.
   5
   6 From: Yuiko Oshino <yuiko.oshino@microchip.com>
   7
   8 [ Upstream commit d461e3da905332189aad546b2ad9adbe6071c7cc ]
   9
  10 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.
  11
  12 Fixes: d0cad871703b898a442e4049c532ec39168e5b57 ("SMSC75XX USB 2.0 Gigabit Ethernet Devices")
  13 Signed-off-by: Yuiko Oshino <yuiko.oshino@microchip.com>
  14 Signed-off-by: David S. Miller <davem@davemloft.net>
  15 Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
  16 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  17 ---
  18  drivers/net/usb/smsc75xx.c |   62 +++++++++++++++++++++++++++++++++++++++++++++
  19  1 file changed, 62 insertions(+)
  20
  21 --- a/drivers/net/usb/smsc75xx.c
  22 +++ b/drivers/net/usb/smsc75xx.c
  23 @@ -82,6 +82,9 @@ static bool turbo_mode = true;
  24  module_param(turbo_mode, bool, 0644);
  25  MODULE_PARM_DESC(turbo_mode, "Enable multiple frames per Rx transaction");
  26
  27 +static int smsc75xx_link_ok_nopm(struct usbnet *dev);
  28 +static int smsc75xx_phy_gig_workaround(struct usbnet *dev);
  29 +
  30  static int __must_check __smsc75xx_read_reg(struct usbnet *dev, u32 index,
  31                                             u32 *data, int in_pm)
  32  {
  33 @@ -852,6 +855,9 @@ static int smsc75xx_phy_initialize(struc
  34                 return -EIO;
  35         }
  36
  37 +       /* phy workaround for gig link */
  38 +       smsc75xx_phy_gig_workaround(dev);
  39 +
  40         smsc75xx_mdio_write(dev->net, dev->mii.phy_id, MII_ADVERTISE,
  41                 ADVERTISE_ALL | ADVERTISE_CSMA | ADVERTISE_PAUSE_CAP |
  42                 ADVERTISE_PAUSE_ASYM);
  43 @@ -987,6 +993,62 @@ static int smsc75xx_wait_ready(struct us
  44         return -EIO;
  45  }
  46
  47 +static int smsc75xx_phy_gig_workaround(struct usbnet *dev)
  48 +{
  49 +       struct mii_if_info *mii = &dev->mii;
  50 +       int ret = 0, timeout = 0;
  51 +       u32 buf, link_up = 0;
  52 +
  53 +       /* Set the phy in Gig loopback */
  54 +       smsc75xx_mdio_write(dev->net, mii->phy_id, MII_BMCR, 0x4040);
  55 +
  56 +       /* Wait for the link up */
  57 +       do {
  58 +               link_up = smsc75xx_link_ok_nopm(dev);
  59 +               usleep_range(10000, 20000);
  60 +               timeout++;
  61 +       } while ((!link_up) && (timeout < 1000));
  62 +
  63 +       if (timeout >= 1000) {
  64 +               netdev_warn(dev->net, "Timeout waiting for PHY link up\n");
  65 +               return -EIO;
  66 +       }
  67 +
  68 +       /* phy reset */
  69 +       ret = smsc75xx_read_reg(dev, PMT_CTL, &buf);
  70 +       if (ret < 0) {
  71 +               netdev_warn(dev->net, "Failed to read PMT_CTL: %d\n", ret);
  72 +               return ret;
  73 +       }
  74 +
  75 +       buf |= PMT_CTL_PHY_RST;
  76 +
  77 +       ret = smsc75xx_write_reg(dev, PMT_CTL, buf);
  78 +       if (ret < 0) {
  79 +               netdev_warn(dev->net, "Failed to write PMT_CTL: %d\n", ret);
  80 +               return ret;
  81 +       }
  82 +
  83 +       timeout = 0;
  84 +       do {
  85 +               usleep_range(10000, 20000);
  86 +               ret = smsc75xx_read_reg(dev, PMT_CTL, &buf);
  87 +               if (ret < 0) {
  88 +                       netdev_warn(dev->net, "Failed to read PMT_CTL: %d\n",
  89 +                                   ret);
  90 +                       return ret;
  91 +               }
  92 +               timeout++;
  93 +       } while ((buf & PMT_CTL_PHY_RST) && (timeout < 100));
  94 +
  95 +       if (timeout >= 100) {
  96 +               netdev_warn(dev->net, "timeout waiting for PHY Reset\n");
  97 +               return -EIO;
  98 +       }
  99 +
 100 +       return 0;
 101 +}
 102 +
 103  static int smsc75xx_reset(struct usbnet *dev)
 104  {
 105         struct smsc75xx_priv *pdata = (struct smsc75xx_priv *)(dev->data[0]);