Re: [PATCH v2] dp83640: Ensure against premature access to PHY registers after reset

[Sasha Levin]

Hi,

[This is an automated email]

This commit has been processed by the -stable helper bot and determined
to be a high probability candidate for -stable trees. (score: 7.2454)

The bot has tested the following trees: v4.16.1, v4.15.16, v4.14.33, v4.9.93, 
v4.4.127.

v4.16.1: Build OK!
v4.15.16: Build OK!
v4.14.33: Build OK!
v4.9.93: Build OK!
v4.4.127: Build OK!

Please let us know if you'd like to have this patch included in a stable tree.

--
Thanks,
Sasha

Re: [PATCH v2] dp83640: Ensure against premature access to PHY registers after reset

[Andrew Lunn]

On Fri, Apr 06, 2018 at 07:08:44PM +0200, Esben Haabendal wrote:
> From: Esben Haabendal 
 
Hi Esben

It it good to have some form of commit message. Something like:

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.


With that, or something similar added:

Reviewed-by: Andrew Lunn 

Andrew

[PATCH v2] dp83640: Ensure against premature access to PHY registers after reset

[Esben Haabendal]

From: Esben Haabendal 

Signed-off-by: Esben Haabendal 
---
 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