[PATCH 2/2] net: phy: marvell-88q2xxx: Prevent reading temperature with asserted reset

[Dimitri Fedrau]

If the PHYs reset is asserted it returns 0xffff for any read operation.
Prevent reading the temperature in this case and return with an I/O error.
Write operations are ignored by the device.

Fixes: a197004cf3c2 ("net: phy: marvell-88q2xxx: Fix temperature measurement with reset-gpios")
Signed-off-by: Dimitri Fedrau <dima.fedrau@xxxxxxxxx>
---
 drivers/net/phy/marvell-88q2xxx.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/phy/marvell-88q2xxx.c b/drivers/net/phy/marvell-88q2xxx.c
index 30d71bfc365597d77c34c48f05390db9d63c4af4..c1ae27057ee34feacb31c2e3c40b2b1769596408 100644
--- a/drivers/net/phy/marvell-88q2xxx.c
+++ b/drivers/net/phy/marvell-88q2xxx.c
@@ -647,6 +647,12 @@ static int mv88q2xxx_hwmon_read(struct device *dev,
 	struct phy_device *phydev = dev_get_drvdata(dev);
 	int ret;
 
+	/* If the PHYs reset is asserted it returns 0xffff for any read
+	 * operation. Return with an I/O error in this case.
+	 */
+	if (phydev->mdio.reset_state == 1)
+		return -EIO;
+
 	switch (attr) {
 	case hwmon_temp_input:
 		ret = phy_read_mmd(phydev, MDIO_MMD_PCS,

-- 
2.39.5