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-rw-r--r--drivers/net/phy/mxl-gpy.c85
1 files changed, 85 insertions, 0 deletions
diff --git a/drivers/net/phy/mxl-gpy.c b/drivers/net/phy/mxl-gpy.c
index 24bae27eedef..cae24091fb6f 100644
--- a/drivers/net/phy/mxl-gpy.c
+++ b/drivers/net/phy/mxl-gpy.c
@@ -9,6 +9,7 @@
#include <linux/module.h>
#include <linux/bitfield.h>
#include <linux/hwmon.h>
+#include <linux/mutex.h>
#include <linux/phy.h>
#include <linux/polynomial.h>
#include <linux/netdevice.h>
@@ -70,6 +71,14 @@
#define VPSPEC1_TEMP_STA 0x0E
#define VPSPEC1_TEMP_STA_DATA GENMASK(9, 0)
+/* Mailbox */
+#define VSPEC1_MBOX_DATA 0x5
+#define VSPEC1_MBOX_ADDRLO 0x6
+#define VSPEC1_MBOX_CMD 0x7
+#define VSPEC1_MBOX_CMD_ADDRHI GENMASK(7, 0)
+#define VSPEC1_MBOX_CMD_RD (0 << 8)
+#define VSPEC1_MBOX_CMD_READY BIT(15)
+
/* WoL */
#define VPSPEC2_WOL_CTL 0x0E06
#define VPSPEC2_WOL_AD01 0x0E08
@@ -77,7 +86,13 @@
#define VPSPEC2_WOL_AD45 0x0E0A
#define WOL_EN BIT(0)
+/* Internal registers, access via mbox */
+#define REG_GPIO0_OUT 0xd3ce00
+
struct gpy_priv {
+ /* serialize mailbox acesses */
+ struct mutex mbox_lock;
+
u8 fw_major;
u8 fw_minor;
};
@@ -187,6 +202,45 @@ static int gpy_hwmon_register(struct phy_device *phydev)
}
#endif
+static int gpy_mbox_read(struct phy_device *phydev, u32 addr)
+{
+ struct gpy_priv *priv = phydev->priv;
+ int val, ret;
+ u16 cmd;
+
+ mutex_lock(&priv->mbox_lock);
+
+ ret = phy_write_mmd(phydev, MDIO_MMD_VEND1, VSPEC1_MBOX_ADDRLO,
+ addr);
+ if (ret)
+ goto out;
+
+ cmd = VSPEC1_MBOX_CMD_RD;
+ cmd |= FIELD_PREP(VSPEC1_MBOX_CMD_ADDRHI, addr >> 16);
+
+ ret = phy_write_mmd(phydev, MDIO_MMD_VEND1, VSPEC1_MBOX_CMD, cmd);
+ if (ret)
+ goto out;
+
+ /* The mbox read is used in the interrupt workaround. It was observed
+ * that a read might take up to 2.5ms. This is also the time for which
+ * the interrupt line is stuck low. To be on the safe side, poll the
+ * ready bit for 10ms.
+ */
+ ret = phy_read_mmd_poll_timeout(phydev, MDIO_MMD_VEND1,
+ VSPEC1_MBOX_CMD, val,
+ (val & VSPEC1_MBOX_CMD_READY),
+ 500, 10000, false);
+ if (ret)
+ goto out;
+
+ ret = phy_read_mmd(phydev, MDIO_MMD_VEND1, VSPEC1_MBOX_DATA);
+
+out:
+ mutex_unlock(&priv->mbox_lock);
+ return ret;
+}
+
static int gpy_config_init(struct phy_device *phydev)
{
int ret;
@@ -201,6 +255,13 @@ static int gpy_config_init(struct phy_device *phydev)
return ret < 0 ? ret : 0;
}
+static bool gpy_has_broken_mdint(struct phy_device *phydev)
+{
+ /* At least these PHYs are known to have broken interrupt handling */
+ return phydev->drv->phy_id == PHY_ID_GPY215B ||
+ phydev->drv->phy_id == PHY_ID_GPY215C;
+}
+
static int gpy_probe(struct phy_device *phydev)
{
struct device *dev = &phydev->mdio.dev;
@@ -218,6 +279,7 @@ static int gpy_probe(struct phy_device *phydev)
if (!priv)
return -ENOMEM;
phydev->priv = priv;
+ mutex_init(&priv->mbox_lock);
fw_version = phy_read(phydev, PHY_FWV);
if (fw_version < 0)
@@ -492,6 +554,29 @@ static irqreturn_t gpy_handle_interrupt(struct phy_device *phydev)
if (!(reg & PHY_IMASK_MASK))
return IRQ_NONE;
+ /* The PHY might leave the interrupt line asserted even after PHY_ISTAT
+ * is read. To avoid interrupt storms, delay the interrupt handling as
+ * long as the PHY drives the interrupt line. An internal bus read will
+ * stall as long as the interrupt line is asserted, thus just read a
+ * random register here.
+ * Because we cannot access the internal bus at all while the interrupt
+ * is driven by the PHY, there is no way to make the interrupt line
+ * unstuck (e.g. by changing the pinmux to GPIO input) during that time
+ * frame. Therefore, polling is the best we can do and won't do any more
+ * harm.
+ * It was observed that this bug happens on link state and link speed
+ * changes on a GPY215B and GYP215C independent of the firmware version
+ * (which doesn't mean that this list is exhaustive).
+ */
+ if (gpy_has_broken_mdint(phydev) &&
+ (reg & (PHY_IMASK_LSTC | PHY_IMASK_LSPC))) {
+ reg = gpy_mbox_read(phydev, REG_GPIO0_OUT);
+ if (reg < 0) {
+ phy_error(phydev);
+ return IRQ_NONE;
+ }
+ }
+
phy_trigger_machine(phydev);
return IRQ_HANDLED;