[RFC PATCH net-next v3 03/20] net: mdio: ipq8064: enlarge sleep after read/write operation

Ansuel Smith
2021-05-04T22:29:40Z

With the use of the qca8k dsa driver, some problem arised related to
port status detection. With a load on a specific port (for example a
simple speed test), the driver starts to behave in a strange way and
garbage data is produced. To address this, enlarge the sleep delay and
address a bug for the reg offset 31 that require additional delay for
this specific reg.

Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
---
drivers/net/mdio/mdio-ipq8064.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/net/mdio/mdio-ipq8064.c b/drivers/net/mdio/mdio-ipq8064.c
index 9862745d1cee..a3f7f9de12b6 100644
--- a/drivers/net/mdio/mdio-ipq8064.c
+++ b/drivers/net/mdio/mdio-ipq8064.c
@@ -65,7 +65,7 @@ ipq8064_mdio_read(struct mii_bus *bus, int phy_addr, int reg_offset)
((reg_offset << MII_REG_SHIFT) & MII_REG_MASK);

regmap_write(priv->base, MII_ADDR_REG_ADDR, miiaddr);
- usleep_range(8, 10);
+ usleep_range(10, 13);

err = ipq8064_mdio_wait_busy(priv);
if (err)
@@ -91,7 +91,14 @@ ipq8064_mdio_write(struct mii_bus *bus, int phy_addr, int reg_offset, u16 data)
((reg_offset << MII_REG_SHIFT) & MII_REG_MASK);

regmap_write(priv->base, MII_ADDR_REG_ADDR, miiaddr);
- usleep_range(8, 10);
+
+ /* For the specific reg 31 extra time is needed or the next
+ * read will produce garbage data.
+ */
+ if (reg_offset == 31)
+ usleep_range(30, 43);
+ else
+ usleep_range(10, 13);

return ipq8064_mdio_wait_busy(priv);
}
--
2.30.2