diff mbox series

[net-next] net: phy: improve genphy_soft_reset

Message ID 9d703dbf-7be0-d4aa-57e2-8e45da5f7cd2@gmail.com
State Accepted
Delegated to: David Miller
Headers show
Series [net-next] net: phy: improve genphy_soft_reset | expand

Commit Message

Heiner Kallweit April 24, 2019, 7:41 p.m. UTC
PHY's behave differently when being reset. Some reset registers to
defaults, some don't. Some trigger an autoneg restart, some don't.

So let's also set the autoneg restart bit when resetting. Then PHY
behavior should be more consistent. Clearing BMCR_ISOLATE serves the
same purpose and is borrowed from genphy_restart_aneg.

BMCR holds the speed / duplex settings in fixed mode. Therefore
we may have an issue if a soft reset resets BMCR to its default.
So better call genphy_setup_forced() afterwards in fixed mode.
We've seen no related complaint in the last >10 yrs, so let's
treat it as an improvement.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/net/phy/phy_device.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

Comments

David Miller April 26, 2019, 3:57 p.m. UTC | #1
From: Heiner Kallweit <hkallweit1@gmail.com>
Date: Wed, 24 Apr 2019 21:41:06 +0200

> PHY's behave differently when being reset. Some reset registers to
> defaults, some don't. Some trigger an autoneg restart, some don't.
> 
> So let's also set the autoneg restart bit when resetting. Then PHY
> behavior should be more consistent. Clearing BMCR_ISOLATE serves the
> same purpose and is borrowed from genphy_restart_aneg.
> 
> BMCR holds the speed / duplex settings in fixed mode. Therefore
> we may have an issue if a soft reset resets BMCR to its default.
> So better call genphy_setup_forced() afterwards in fixed mode.
> We've seen no related complaint in the last >10 yrs, so let's
> treat it as an improvement.
> 
> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>

Applied.
diff mbox series

Patch

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index b9192ae92..f794ff3a1 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1815,13 +1815,25 @@  EXPORT_SYMBOL(genphy_read_status);
  */
 int genphy_soft_reset(struct phy_device *phydev)
 {
+	u16 res = BMCR_RESET;
 	int ret;
 
-	ret = phy_set_bits(phydev, MII_BMCR, BMCR_RESET);
+	if (phydev->autoneg == AUTONEG_ENABLE)
+		res |= BMCR_ANRESTART;
+
+	ret = phy_modify(phydev, MII_BMCR, BMCR_ISOLATE, res);
 	if (ret < 0)
 		return ret;
 
-	return phy_poll_reset(phydev);
+	ret = phy_poll_reset(phydev);
+	if (ret)
+		return ret;
+
+	/* BMCR may be reset to defaults */
+	if (phydev->autoneg == AUTONEG_DISABLE)
+		ret = genphy_setup_forced(phydev);
+
+	return ret;
 }
 EXPORT_SYMBOL(genphy_soft_reset);