2019-10-16 10:57:17

by Yonglong Liu

Subject: [PATCH net] net: phy: Fix "link partner" information disappear issue

Some drivers just call phy_ethtool_ksettings_set() to set the
links, for those phy drivers that use genphy_read_status(), if
autoneg is on, and the link is up, than execute "ethtool -s
ethx autoneg on" will cause "link partner" information disappear.

The call trace is phy_ethtool_ksettings_set()->phy_start_aneg()
->linkmode_zero(phydev->lp_advertising)->genphy_read_status(),
the link didn't change, so genphy_read_status() just return, and
phydev->lp_advertising is zero now.

This patch moves the clear operation of lp_advertising from
phy_start_aneg() to genphy_read_lpa()/genphy_c45_read_lpa(), and
if autoneg on and autoneg not complete, just clear what the
generic functions care about.

Fixes: 88d6272acaaa ("net: phy: avoid unneeded MDIO reads in genphy_read_status")
Signed-off-by: Yonglong Liu <[email protected]>
---
drivers/net/phy/phy-c45.c | 2 ++
drivers/net/phy/phy.c | 3 ---
drivers/net/phy/phy_device.c | 11 ++++++++++-
3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/net/phy/phy-c45.c b/drivers/net/phy/phy-c45.c
index 7935593..a1caeee 100644
--- a/drivers/net/phy/phy-c45.c
+++ b/drivers/net/phy/phy-c45.c
@@ -323,6 +323,8 @@ int genphy_c45_read_pma(struct phy_device *phydev)
{
int val;

+ linkmode_zero(phydev->lp_advertising);
+
val = phy_read_mmd(phydev, MDIO_MMD_PMAPMD, MDIO_CTRL1);
if (val < 0)
return val;
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 119e6f4..105d389b 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -572,9 +572,6 @@ int phy_start_aneg(struct phy_device *phydev)
if (AUTONEG_DISABLE == phydev->autoneg)
phy_sanitize_settings(phydev);

- /* Invalidate LP advertising flags */
- linkmode_zero(phydev->lp_advertising);
-
err = phy_config_aneg(phydev);
if (err < 0)
goto out_unlock;
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 9d2bbb1..adb66a2 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1787,7 +1787,14 @@ int genphy_read_lpa(struct phy_device *phydev)
{
int lpa, lpagb;

- if (phydev->autoneg == AUTONEG_ENABLE && phydev->autoneg_complete) {
+ if (phydev->autoneg == AUTONEG_ENABLE) {
+ if (!phydev->autoneg_complete) {
+ mii_stat1000_mod_linkmode_lpa_t(phydev->lp_advertising,
+ 0);
+ mii_lpa_mod_linkmode_lpa_t(phydev->lp_advertising, 0);
+ return 0;
+ }
+
if (phydev->is_gigabit_capable) {
lpagb = phy_read(phydev, MII_STAT1000);
if (lpagb < 0)
@@ -1815,6 +1822,8 @@ int genphy_read_lpa(struct phy_device *phydev)
return lpa;

mii_lpa_mod_linkmode_lpa_t(phydev->lp_advertising, lpa);
+ } else {
+ linkmode_zero(phydev->lp_advertising);
}

return 0;
--
2.8.1

2019-10-17 12:54:51

by Heiner Kallweit

Subject: Re: [PATCH net] net: phy: Fix "link partner" information disappear issue

On 16.10.2019 04:30, Yonglong Liu wrote:
> Some drivers just call phy_ethtool_ksettings_set() to set the
> links, for those phy drivers that use genphy_read_status(), if
> autoneg is on, and the link is up, than execute "ethtool -s
> ethx autoneg on" will cause "link partner" information disappear.
>
> The call trace is phy_ethtool_ksettings_set()->phy_start_aneg()
> ->linkmode_zero(phydev->lp_advertising)->genphy_read_status(),
> the link didn't change, so genphy_read_status() just return, and
> phydev->lp_advertising is zero now.
>
> This patch moves the clear operation of lp_advertising from
> phy_start_aneg() to genphy_read_lpa()/genphy_c45_read_lpa(), and
> if autoneg on and autoneg not complete, just clear what the
> generic functions care about.
>
> Fixes: 88d6272acaaa ("net: phy: avoid unneeded MDIO reads in genphy_read_status")
> Signed-off-by: Yonglong Liu <[email protected]>
> ---

Reviewed-by: Heiner Kallweit <[email protected]>

2019-10-17 13:32:33

by David Miller

Subject: Re: [PATCH net] net: phy: Fix "link partner" information disappear issue

From: Yonglong Liu <[email protected]>
Date: Wed, 16 Oct 2019 10:30:39 +0800

> Some drivers just call phy_ethtool_ksettings_set() to set the
> links, for those phy drivers that use genphy_read_status(), if
> autoneg is on, and the link is up, than execute "ethtool -s
> ethx autoneg on" will cause "link partner" information disappear.
>
> The call trace is phy_ethtool_ksettings_set()->phy_start_aneg()
> ->linkmode_zero(phydev->lp_advertising)->genphy_read_status(),
> the link didn't change, so genphy_read_status() just return, and
> phydev->lp_advertising is zero now.
>
> This patch moves the clear operation of lp_advertising from
> phy_start_aneg() to genphy_read_lpa()/genphy_c45_read_lpa(), and
> if autoneg on and autoneg not complete, just clear what the
> generic functions care about.
>
> Fixes: 88d6272acaaa ("net: phy: avoid unneeded MDIO reads in genphy_read_status")
> Signed-off-by: Yonglong Liu <[email protected]>

Applied and queued up for -stable, thank you.