Re: [PATCH v3] dp83640: Ensure against premature access to PHY registers after reset

[David Miller]

From: Esben Haabendal 
Date: Sun,  8 Apr 2018 22:17:01 +0200

> From: Esben Haabendal 
> 
> The datasheet specifies a 3uS pause after performing a software
> reset. The default implementation of genphy_soft_reset() does not
> provide this, so implement soft_reset with the needed pause.
> 
> Signed-off-by: Esben Haabendal 
> Reviewed-by: Andrew Lunn 

Applied, thank you.

[PATCH v3] dp83640: Ensure against premature access to PHY registers after reset

[Esben Haabendal]

From: Esben Haabendal 

The datasheet specifies a 3uS pause after performing a software
reset. The default implementation of genphy_soft_reset() does not
provide this, so implement soft_reset with the needed pause.

Signed-off-by: Esben Haabendal 
Reviewed-by: Andrew Lunn 
---
 drivers/net/phy/dp83640.c | 18 ++
 1 file changed, 18 insertions(+)

diff --git a/drivers/net/phy/dp83640.c b/drivers/net/phy/dp83640.c
index 654f42d00092..a6c87793d899 100644
--- a/drivers/net/phy/dp83640.c
+++ b/drivers/net/phy/dp83640.c
@@ -1207,6 +1207,23 @@ static void dp83640_remove(struct phy_device *phydev)
kfree(dp83640);
 }
 
+static int dp83640_soft_reset(struct phy_device *phydev)
+{
+   int ret;
+
+   ret = genphy_soft_reset(phydev);
+   if (ret < 0)
+   return ret;
+
+   /* From DP83640 datasheet: "Software driver code must wait 3 us
+* following a software reset before allowing further serial MII
+* operations with the DP83640."
+*/
+   udelay(10); /* Taking udelay inaccuracy into account */
+
+   return 0;
+}
+
 static int dp83640_config_init(struct phy_device *phydev)
 {
struct dp83640_private *dp83640 = phydev->priv;
@@ -1501,6 +1518,7 @@ static struct phy_driver dp83640_driver = {
.flags  = PHY_HAS_INTERRUPT,
.probe  = dp83640_probe,
.remove = dp83640_remove,
+   .soft_reset = dp83640_soft_reset,
.config_init= dp83640_config_init,
.ack_interrupt  = dp83640_ack_interrupt,
.config_intr= dp83640_config_intr,
-- 
2.16.3