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path: root/drivers/net/phy/meson-gxl.c
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Diffstat (limited to 'drivers/net/phy/meson-gxl.c')
-rw-r--r--drivers/net/phy/meson-gxl.c74
1 files changed, 73 insertions, 1 deletions
diff --git a/drivers/net/phy/meson-gxl.c b/drivers/net/phy/meson-gxl.c
index 1ea69b7585d9..842eb871a6e3 100644
--- a/drivers/net/phy/meson-gxl.c
+++ b/drivers/net/phy/meson-gxl.c
@@ -22,6 +22,7 @@
#include <linux/ethtool.h>
#include <linux/phy.h>
#include <linux/netdevice.h>
+#include <linux/bitfield.h>
static int meson_gxl_config_init(struct phy_device *phydev)
{
@@ -50,6 +51,77 @@ static int meson_gxl_config_init(struct phy_device *phydev)
return 0;
}
+/* This function is provided to cope with the possible failures of this phy
+ * during aneg process. When aneg fails, the PHY reports that aneg is done
+ * but the value found in MII_LPA is wrong:
+ * - Early failures: MII_LPA is just 0x0001. if MII_EXPANSION reports that
+ * the link partner (LP) supports aneg but the LP never acked our base
+ * code word, it is likely that we never sent it to begin with.
+ * - Late failures: MII_LPA is filled with a value which seems to make sense
+ * but it actually is not what the LP is advertising. It seems that we
+ * can detect this using a magic bit in the WOL bank (reg 12 - bit 12).
+ * If this particular bit is not set when aneg is reported being done,
+ * it means MII_LPA is likely to be wrong.
+ *
+ * In both case, forcing a restart of the aneg process solve the problem.
+ * When this failure happens, the first retry is usually successful but,
+ * in some cases, it may take up to 6 retries to get a decent result
+ */
+static int meson_gxl_read_status(struct phy_device *phydev)
+{
+ int ret, wol, lpa, exp;
+
+ if (phydev->autoneg == AUTONEG_ENABLE) {
+ ret = genphy_aneg_done(phydev);
+ if (ret < 0)
+ return ret;
+ else if (!ret)
+ goto read_status_continue;
+
+ /* Need to access WOL bank, make sure the access is open */
+ ret = phy_write(phydev, 0x14, 0x0000);
+ if (ret)
+ return ret;
+ ret = phy_write(phydev, 0x14, 0x0400);
+ if (ret)
+ return ret;
+ ret = phy_write(phydev, 0x14, 0x0000);
+ if (ret)
+ return ret;
+ ret = phy_write(phydev, 0x14, 0x0400);
+ if (ret)
+ return ret;
+
+ /* Request LPI_STATUS WOL register */
+ ret = phy_write(phydev, 0x14, 0x8D80);
+ if (ret)
+ return ret;
+
+ /* Read LPI_STATUS value */
+ wol = phy_read(phydev, 0x15);
+ if (wol < 0)
+ return wol;
+
+ lpa = phy_read(phydev, MII_LPA);
+ if (lpa < 0)
+ return lpa;
+
+ exp = phy_read(phydev, MII_EXPANSION);
+ if (exp < 0)
+ return exp;
+
+ if (!(wol & BIT(12)) ||
+ ((exp & EXPANSION_NWAY) && !(lpa & LPA_LPACK))) {
+ /* Looks like aneg failed after all */
+ phydev_dbg(phydev, "LPA corruption - aneg restart\n");
+ return genphy_restart_aneg(phydev);
+ }
+ }
+
+read_status_continue:
+ return genphy_read_status(phydev);
+}
+
static struct phy_driver meson_gxl_phy[] = {
{
.phy_id = 0x01814400,
@@ -60,7 +132,7 @@ static struct phy_driver meson_gxl_phy[] = {
.config_init = meson_gxl_config_init,
.config_aneg = genphy_config_aneg,
.aneg_done = genphy_aneg_done,
- .read_status = genphy_read_status,
+ .read_status = meson_gxl_read_status,
.suspend = genphy_suspend,
.resume = genphy_resume,
},