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 call genphy_read_lpa() before the link state judgement
to fix this problem.
Fixes: 88d6272acaaa ("net: phy: avoid unneeded MDIO reads in genphy_read_status")
Signed-off-by: Yonglong Liu <[email protected]>
---
drivers/net/phy/phy_device.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 9d2bbb1..ef3073c 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1839,6 +1839,10 @@ int genphy_read_status(struct phy_device *phydev)
if (err)
return err;
+ err = genphy_read_lpa(phydev);
+ if (err < 0)
+ return err;
+
/* why bother the PHY if nothing can have changed */
if (phydev->autoneg == AUTONEG_ENABLE && old_link && phydev->link)
return 0;
@@ -1848,10 +1852,6 @@ int genphy_read_status(struct phy_device *phydev)
phydev->pause = 0;
phydev->asym_pause = 0;
- err = genphy_read_lpa(phydev);
- if (err < 0)
- return err;
-
if (phydev->autoneg == AUTONEG_ENABLE && phydev->autoneg_complete) {
phy_resolve_aneg_linkmode(phydev);
} else if (phydev->autoneg == AUTONEG_DISABLE) {
--
2.8.1
On 10.10.2019 11:30, 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.
>
I think that clearing link partner advertising info in
phy_start_aneg() is questionable. If advertising doesn't change
then phy_config_aneg() basically is a no-op. Instead we may have
to clear the link partner advertising info in genphy_read_lpa()
if aneg is disabled or aneg isn't completed (basically the same
as in genphy_c45_read_lpa()). Something like:
if (!phydev->autoneg_complete) { /* also covers case that aneg is disabled */
linkmode_zero(phydev->lp_advertising);
} else if (phydev->autoneg == AUTONEG_ENABLE) {
...
}
> This patch call genphy_read_lpa() before the link state judgement
> to fix this problem.
>
> Fixes: 88d6272acaaa ("net: phy: avoid unneeded MDIO reads in genphy_read_status")
> Signed-off-by: Yonglong Liu <[email protected]>
> ---
> drivers/net/phy/phy_device.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index 9d2bbb1..ef3073c 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -1839,6 +1839,10 @@ int genphy_read_status(struct phy_device *phydev)
> if (err)
> return err;
>
> + err = genphy_read_lpa(phydev);
> + if (err < 0)
> + return err;
> +
> /* why bother the PHY if nothing can have changed */
> if (phydev->autoneg == AUTONEG_ENABLE && old_link && phydev->link)
> return 0;
> @@ -1848,10 +1852,6 @@ int genphy_read_status(struct phy_device *phydev)
> phydev->pause = 0;
> phydev->asym_pause = 0;
>
> - err = genphy_read_lpa(phydev);
> - if (err < 0)
> - return err;
> -
> if (phydev->autoneg == AUTONEG_ENABLE && phydev->autoneg_complete) {
> phy_resolve_aneg_linkmode(phydev);
> } else if (phydev->autoneg == AUTONEG_DISABLE) {
>
On 2019/10/11 3:17, Heiner Kallweit wrote:
> On 10.10.2019 11:30, 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.
>>
> I think that clearing link partner advertising info in
> phy_start_aneg() is questionable. If advertising doesn't change
> then phy_config_aneg() basically is a no-op. Instead we may have
> to clear the link partner advertising info in genphy_read_lpa()
> if aneg is disabled or aneg isn't completed (basically the same
> as in genphy_c45_read_lpa()). Something like:
>
> if (!phydev->autoneg_complete) { /* also covers case that aneg is disabled */
> linkmode_zero(phydev->lp_advertising);
> } else if (phydev->autoneg == AUTONEG_ENABLE) {
> ...
> }
>
If clear the link partner advertising info in genphy_read_lpa() and
genphy_c45_read_lpa(), for the drivers that use genphy_read_status()
is ok, but for those drivers that use there own read_status() may
have problem, like aqr_read_status(), it will update lp_advertising
first, and than call genphy_c45_read_status(), so will cause
lp_advertising lost.
Another question, please see genphy_c45_read_status(), if clear the
link partner advertising info in genphy_c45_read_lpa(), if autoneg is
off, phydev->lp_advertising will not clear.
>> This patch call genphy_read_lpa() before the link state judgement
>> to fix this problem.
>>
>> Fixes: 88d6272acaaa ("net: phy: avoid unneeded MDIO reads in genphy_read_status")
>> Signed-off-by: Yonglong Liu <[email protected]>
>> ---
>> drivers/net/phy/phy_device.c | 8 ++++----
>> 1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
>> index 9d2bbb1..ef3073c 100644
>> --- a/drivers/net/phy/phy_device.c
>> +++ b/drivers/net/phy/phy_device.c
>> @@ -1839,6 +1839,10 @@ int genphy_read_status(struct phy_device *phydev)
>> if (err)
>> return err;
>>
>> + err = genphy_read_lpa(phydev);
>> + if (err < 0)
>> + return err;
>> +
>> /* why bother the PHY if nothing can have changed */
>> if (phydev->autoneg == AUTONEG_ENABLE && old_link && phydev->link)
>> return 0;
>> @@ -1848,10 +1852,6 @@ int genphy_read_status(struct phy_device *phydev)
>> phydev->pause = 0;
>> phydev->asym_pause = 0;
>>
>> - err = genphy_read_lpa(phydev);
>> - if (err < 0)
>> - return err;
>> -
>> if (phydev->autoneg == AUTONEG_ENABLE && phydev->autoneg_complete) {
>> phy_resolve_aneg_linkmode(phydev);
>> } else if (phydev->autoneg == AUTONEG_DISABLE) {
>>
>
>
> .
>
On 11.10.2019 07:55, Yonglong Liu wrote:
>
>
> On 2019/10/11 3:17, Heiner Kallweit wrote:
>> On 10.10.2019 11:30, 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.
>>>
>> I think that clearing link partner advertising info in
>> phy_start_aneg() is questionable. If advertising doesn't change
>> then phy_config_aneg() basically is a no-op. Instead we may have
>> to clear the link partner advertising info in genphy_read_lpa()
>> if aneg is disabled or aneg isn't completed (basically the same
>> as in genphy_c45_read_lpa()). Something like:
>>
>> if (!phydev->autoneg_complete) { /* also covers case that aneg is disabled */
>> linkmode_zero(phydev->lp_advertising);
>> } else if (phydev->autoneg == AUTONEG_ENABLE) {
>> ...
>> }
>>
>
> If clear the link partner advertising info in genphy_read_lpa() and
> genphy_c45_read_lpa(), for the drivers that use genphy_read_status()
> is ok, but for those drivers that use there own read_status() may
> have problem, like aqr_read_status(), it will update lp_advertising
> first, and than call genphy_c45_read_status(), so will cause
> lp_advertising lost.
>
Right, in genphy_read_lpa() we shouldn't clear all lpa bits but only
those ones the generic functions care about. Basically the same as
in the c45 version. Then a vendor-specific part isn't affected.
aqr_read_status() is a good example. It deals with 1Gbps mode that
isn't covered by the generic c45 functions. Therefore the 1Gbps-related
bits won't be overwritten by the generic functions.
> Another question, please see genphy_c45_read_status(), if clear the
> link partner advertising info in genphy_c45_read_lpa(), if autoneg is
> off, phydev->lp_advertising will not clear.
>
If autoneg is off, lp_advertising should never be set, so there's
nothing to clear. However we may have to look at the case that user
switches to fixed speed mode via ethtool.
>>> This patch call genphy_read_lpa() before the link state judgement
>>> to fix this problem.
>>>
>>> Fixes: 88d6272acaaa ("net: phy: avoid unneeded MDIO reads in genphy_read_status")
>>> Signed-off-by: Yonglong Liu <[email protected]>
>>> ---
>>> drivers/net/phy/phy_device.c | 8 ++++----
>>> 1 file changed, 4 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
>>> index 9d2bbb1..ef3073c 100644
>>> --- a/drivers/net/phy/phy_device.c
>>> +++ b/drivers/net/phy/phy_device.c
>>> @@ -1839,6 +1839,10 @@ int genphy_read_status(struct phy_device *phydev)
>>> if (err)
>>> return err;
>>>
>>> + err = genphy_read_lpa(phydev);
>>> + if (err < 0)
>>> + return err;
>>> +
>>> /* why bother the PHY if nothing can have changed */
>>> if (phydev->autoneg == AUTONEG_ENABLE && old_link && phydev->link)
>>> return 0;
>>> @@ -1848,10 +1852,6 @@ int genphy_read_status(struct phy_device *phydev)
>>> phydev->pause = 0;
>>> phydev->asym_pause = 0;
>>>
>>> - err = genphy_read_lpa(phydev);
>>> - if (err < 0)
>>> - return err;
>>> -
>>> if (phydev->autoneg == AUTONEG_ENABLE && phydev->autoneg_complete) {
>>> phy_resolve_aneg_linkmode(phydev);
>>> } else if (phydev->autoneg == AUTONEG_DISABLE) {
>>>
>>
>>
>> .
>>
>
>