[PATCH RFC v2 0/3] phylib EEE updates

[PATCH RFC v2 0/3] phylib EEE updates

[Russell King - ARM Linux]

Florian,

This series of patches depends on the previous set of changes, and is
therefore net-next material.

While testing the EEE code, I discovered a number of issues:

1. It is possible to enable advertisment of EEE modes which are not
   supported by the hardware.  We omit to check the supported modes
   and mask off those modes that are not supported before writing the
   EEE advertisment register.

2. We need to restart autonegotiation after a change of the EEE
   advertisment, otherwise the link partner does not see the updated
   EEE modes.

3. SGMII connected PHYs are also capable of supporting EEE.

I'm not too sure why we have the test in phylib for the interface mode,
as the list of interface modes that support EEE is likely to increase
(eg, 10G interface modes have provision to support EEE mode.)  I did
think about killing the test, but the older interface modes probably
don't support it.  Any thoughts on what to do about that - maybe the
test should be reversed to exclude those modes which definitely don't
support EEE?

 drivers/net/phy/phy.c | 29 ++++++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

v2: fix "phy_restart_aneg" build error identified by 0-day
   
-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
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[PATCH RFC v2 1/3] net: phy: avoid setting unsupported EEE advertisments

[Russell King]

We currently allow userspace to set any EEE advertisments it desires,
whether or not the PHY supports them.  For example:

 # ethtool --set-eee eth1 advertise 0xffffffff
 # ethtool --show-eee eth1
 EEE Settings for eth1:
        EEE status: disabled
        Tx LPI: disabled
        Supported EEE link modes:  100baseT/Full
                                   1000baseT/Full
                                   10000baseT/Full
        Advertised EEE link modes:  100baseT/Full
                                    1000baseT/Full
                                    1000baseKX/Full
                                    10000baseT/Full
                                    10000baseKX4/Full
                                    10000baseKR/Full

Clearly, this is not sane, we should only allow link modes that are
supported to be advertised (as we do elsewhere.)  Ensure that we mask
the MDIO_AN_EEE_ADV value with the capabilities retrieved from the
MDIO_PCS_EEE_ABLE register.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 drivers/net/phy/phy.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index ba4676ee9018..7b1c93b0233a 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -1332,17 +1332,22 @@ EXPORT_SYMBOL(phy_ethtool_get_eee);
  */
 int phy_ethtool_set_eee(struct phy_device *phydev, struct ethtool_eee *data)
 {
-	int val = ethtool_adv_to_mmd_eee_adv_t(data->advertised);
+	int cap, adv;
 
 	if (!phydev->drv)
 		return -EIO;
 
-	/* Mask prohibited EEE modes */
-	val &= ~phydev->eee_broken_modes;
+	/* Get Supported EEE */
+	cap = phy_read_mmd(phydev, MDIO_MMD_PCS, MDIO_PCS_EEE_ABLE);
+	if (cap < 0)
+		return cap;
 
-	phy_write_mmd(phydev, MDIO_MMD_AN, MDIO_AN_EEE_ADV, val);
+	adv = ethtool_adv_to_mmd_eee_adv_t(data->advertised) & cap;
 
-	return 0;
+	/* Mask prohibited EEE modes */
+	adv &= ~phydev->eee_broken_modes;
+
+	return phy_write_mmd(phydev, MDIO_MMD_AN, MDIO_AN_EEE_ADV, adv);
 }
 EXPORT_SYMBOL(phy_ethtool_set_eee);
 
-- 
2.7.4

[PATCH RFC v2 2/3] net: phy: restart phy autonegotiation after EEE advertisment change

[Russell King]

When the EEE advertisment is changed, we should restart autonegotiation
to update the link partner with the new EEE settings.  Add this trigger
but only if the advertisment has changed.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 drivers/net/phy/phy.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 7b1c93b0233a..345251f21699 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -1332,7 +1332,7 @@ EXPORT_SYMBOL(phy_ethtool_get_eee);
  */
 int phy_ethtool_set_eee(struct phy_device *phydev, struct ethtool_eee *data)
 {
-	int cap, adv;
+	int cap, old_adv, adv, ret;
 
 	if (!phydev->drv)
 		return -EIO;
@@ -1342,12 +1342,29 @@ int phy_ethtool_set_eee(struct phy_device *phydev, struct ethtool_eee *data)
 	if (cap < 0)
 		return cap;
 
+	old_adv = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_AN_EEE_ADV);
+	if (old_adv < 0)
+		return old_adv;
+
 	adv = ethtool_adv_to_mmd_eee_adv_t(data->advertised) & cap;
 
 	/* Mask prohibited EEE modes */
 	adv &= ~phydev->eee_broken_modes;
 
-	return phy_write_mmd(phydev, MDIO_MMD_AN, MDIO_AN_EEE_ADV, adv);
+	if (old_adv != adv) {
+		ret = phy_write_mmd(phydev, MDIO_MMD_AN, MDIO_AN_EEE_ADV, adv);
+		if (ret < 0)
+			return ret;
+
+		/* Restart autonegotiation so the new modes get sent to the
+		 * link partner.
+		 */
+		ret = genphy_restart_aneg(phydev);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
 }
 EXPORT_SYMBOL(phy_ethtool_set_eee);
 
-- 
2.7.4

[PATCH RFC v2 3/3] net: phy: allow EEE with SGMII interface modes

[Russell King]

As EEE is able to work in SGMII mode as well, add it to the list of
permissable EEE modes that phy_init_eee() will accept.  This is
necessary so that EEE can work with an 88E1512 connected in SGMII mode.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 drivers/net/phy/phy.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 345251f21699..3529cc8bec10 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -1215,6 +1215,7 @@ int phy_init_eee(struct phy_device *phydev, bool clk_stop_enable)
 	if ((phydev->duplex == DUPLEX_FULL) &&
 	    ((phydev->interface == PHY_INTERFACE_MODE_MII) ||
 	    (phydev->interface == PHY_INTERFACE_MODE_GMII) ||
+	     phydev->interface == PHY_INTERFACE_MODE_SGMII ||
 	     phy_interface_is_rgmii(phydev) ||
 	     phy_is_internal(phydev))) {
 		int eee_lp, eee_cap, eee_adv;
-- 
2.7.4

Re: [PATCH RFC v2 3/3] net: phy: allow EEE with SGMII interface modes

[Florian Fainelli]

On 03/27/2017 02:59 AM, Russell King wrote:
> As EEE is able to work in SGMII mode as well, add it to the list of
> permissable EEE modes that phy_init_eee() will accept.  This is
> necessary so that EEE can work with an 88E1512 connected in SGMII mode.

As you mention in your cover letter, we should probably reverse this
test and make it reject modes where EEE has no chance of being supported
at all.

Other than that:

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
-- 
Florian

Re: [PATCH RFC v2 3/3] net: phy: allow EEE with SGMII interface modes

[Russell King - ARM Linux]

On Mon, Mar 27, 2017 at 09:47:31AM -0700, Florian Fainelli wrote:
> On 03/27/2017 02:59 AM, Russell King wrote:
> > As EEE is able to work in SGMII mode as well, add it to the list of
> > permissable EEE modes that phy_init_eee() will accept.  This is
> > necessary so that EEE can work with an 88E1512 connected in SGMII mode.
> 
> As you mention in your cover letter, we should probably reverse this
> test and make it reject modes where EEE has no chance of being supported
> at all.

Want me to re-spin?  Any thought on which interface modes we should
explicitly exclude?

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.

Re: [PATCH RFC v2 3/3] net: phy: allow EEE with SGMII interface modes

[Florian Fainelli]

On 03/27/2017 10:00 AM, Russell King - ARM Linux wrote:
> On Mon, Mar 27, 2017 at 09:47:31AM -0700, Florian Fainelli wrote:
>> On 03/27/2017 02:59 AM, Russell King wrote:
>>> As EEE is able to work in SGMII mode as well, add it to the list of
>>> permissable EEE modes that phy_init_eee() will accept.  This is
>>> necessary so that EEE can work with an 88E1512 connected in SGMII mode.
>>
>> As you mention in your cover letter, we should probably reverse this
>> test and make it reject modes where EEE has no chance of being supported
>> at all.
> 
> Want me to re-spin?  Any thought on which interface modes we should
> explicitly exclude?

It actually sounds like we should just kill the check entirely, it does
not appear that any of the interface mode would not fundamentally be
able to support EEE, because the "lowest" mode we support is MII, and
even there it's quite possible to support EEE.
-- 
Florian

Re: [PATCH RFC v2 2/3] net: phy: restart phy autonegotiation after EEE advertisment change

[Florian Fainelli]

On 03/27/2017 02:58 AM, Russell King wrote:
> When the EEE advertisment is changed, we should restart autonegotiation
> to update the link partner with the new EEE settings.  Add this trigger
> but only if the advertisment has changed.
> 
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
-- 
Florian

Re: [PATCH RFC v2 1/3] net: phy: avoid setting unsupported EEE advertisments

[Florian Fainelli]

On 03/27/2017 02:58 AM, Russell King wrote:
> We currently allow userspace to set any EEE advertisments it desires,
> whether or not the PHY supports them.  For example:
> 
>  # ethtool --set-eee eth1 advertise 0xffffffff
>  # ethtool --show-eee eth1
>  EEE Settings for eth1:
>         EEE status: disabled
>         Tx LPI: disabled
>         Supported EEE link modes:  100baseT/Full
>                                    1000baseT/Full
>                                    10000baseT/Full
>         Advertised EEE link modes:  100baseT/Full
>                                     1000baseT/Full
>                                     1000baseKX/Full
>                                     10000baseT/Full
>                                     10000baseKX4/Full
>                                     10000baseKR/Full
> 
> Clearly, this is not sane, we should only allow link modes that are
> supported to be advertised (as we do elsewhere.)  Ensure that we mask
> the MDIO_AN_EEE_ADV value with the capabilities retrieved from the
> MDIO_PCS_EEE_ABLE register.
> 
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
-- 
Florian

Re: [PATCH RFC v2 3/3] net: phy: allow EEE with SGMII interface modes

[Russell King - ARM Linux]

On Mon, Mar 27, 2017 at 11:03:12AM -0700, Florian Fainelli wrote:
> On 03/27/2017 10:00 AM, Russell King - ARM Linux wrote:
> > On Mon, Mar 27, 2017 at 09:47:31AM -0700, Florian Fainelli wrote:
> >> On 03/27/2017 02:59 AM, Russell King wrote:
> >>> As EEE is able to work in SGMII mode as well, add it to the list of
> >>> permissable EEE modes that phy_init_eee() will accept.  This is
> >>> necessary so that EEE can work with an 88E1512 connected in SGMII mode.
> >>
> >> As you mention in your cover letter, we should probably reverse this
> >> test and make it reject modes where EEE has no chance of being supported
> >> at all.
> > 
> > Want me to re-spin?  Any thought on which interface modes we should
> > explicitly exclude?
> 
> It actually sounds like we should just kill the check entirely, it does
> not appear that any of the interface mode would not fundamentally be
> able to support EEE, because the "lowest" mode we support is MII, and
> even there it's quite possible to support EEE.

Right, so it looks like the test reduces down to just:

	if (phydev->duplex == DUPLEX_FULL) {

agreed?

-- 
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FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.

Re: [PATCH RFC v2 3/3] net: phy: allow EEE with SGMII interface modes

[Florian Fainelli]

On 03/27/2017 12:47 PM, Russell King - ARM Linux wrote:
> On Mon, Mar 27, 2017 at 11:03:12AM -0700, Florian Fainelli wrote:
>> On 03/27/2017 10:00 AM, Russell King - ARM Linux wrote:
>>> On Mon, Mar 27, 2017 at 09:47:31AM -0700, Florian Fainelli wrote:
>>>> On 03/27/2017 02:59 AM, Russell King wrote:
>>>>> As EEE is able to work in SGMII mode as well, add it to the list of
>>>>> permissable EEE modes that phy_init_eee() will accept.  This is
>>>>> necessary so that EEE can work with an 88E1512 connected in SGMII mode.
>>>>
>>>> As you mention in your cover letter, we should probably reverse this
>>>> test and make it reject modes where EEE has no chance of being supported
>>>> at all.
>>>
>>> Want me to re-spin?  Any thought on which interface modes we should
>>> explicitly exclude?
>>
>> It actually sounds like we should just kill the check entirely, it does
>> not appear that any of the interface mode would not fundamentally be
>> able to support EEE, because the "lowest" mode we support is MII, and
>> even there it's quite possible to support EEE.
> 
> Right, so it looks like the test reduces down to just:
> 
> 	if (phydev->duplex == DUPLEX_FULL) {
> 
> agreed?

Yes indeed. Thanks!
-- 
Florian

Re: [PATCH RFC v2 3/3] net: phy: allow EEE with SGMII interface modes

[Russell King - ARM Linux]

Here's the revised patch as requested.

Thanks.

8<===
From: Russell King <rmk+kernel@armlinux.org.uk>
Subject: [PATCH] net: phy: allow EEE with any interface mode

EEE is able to work in any PHY interface mode, there is nothing which
fundamentally restricts it to only a few modes.  For example, EEE works
in SGMII mode with the Marvell 88E1512.

Rather than just adding SGMII mode to the list, Florian suggests
removing the list of interface modes entirely:

  It actually sounds like we should just kill the check entirely,
  it does not appear that any of the interface mode would not
  fundamentally be able to support EEE, because the "lowest" mode
  we support is MII, and even there it's quite possible to support
  EEE.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 drivers/net/phy/phy.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 345251f21699..867c42154087 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -1208,15 +1208,8 @@ int phy_init_eee(struct phy_device *phydev, bool clk_stop_enable)
 		return -EIO;
 
 	/* According to 802.3az,the EEE is supported only in full duplex-mode.
-	 * Also EEE feature is active when core is operating with MII, GMII
-	 * or RGMII (all kinds). Internal PHYs are also allowed to proceed and
-	 * should return an error if they do not support EEE.
 	 */
-	if ((phydev->duplex == DUPLEX_FULL) &&
-	    ((phydev->interface == PHY_INTERFACE_MODE_MII) ||
-	    (phydev->interface == PHY_INTERFACE_MODE_GMII) ||
-	     phy_interface_is_rgmii(phydev) ||
-	     phy_is_internal(phydev))) {
+	if (phydev->duplex == DUPLEX_FULL) {
 		int eee_lp, eee_cap, eee_adv;
 		u32 lp, cap, adv;
 		int status;
-- 
2.7.4


-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
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Re: [PATCH RFC v2 3/3] net: phy: allow EEE with SGMII interface modes

[Florian Fainelli]

On 03/27/2017 01:15 PM, Russell King - ARM Linux wrote:
> Here's the revised patch as requested.
> 
> Thanks.
> 
> 8<===
> From: Russell King <rmk+kernel@armlinux.org.uk>
> Subject: [PATCH] net: phy: allow EEE with any interface mode
> 
> EEE is able to work in any PHY interface mode, there is nothing which
> fundamentally restricts it to only a few modes.  For example, EEE works
> in SGMII mode with the Marvell 88E1512.
> 
> Rather than just adding SGMII mode to the list, Florian suggests
> removing the list of interface modes entirely:
> 
>   It actually sounds like we should just kill the check entirely,
>   it does not appear that any of the interface mode would not
>   fundamentally be able to support EEE, because the "lowest" mode
>   we support is MII, and even there it's quite possible to support
>   EEE.
> 
> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>

I think David will require you to resubmit this as an entire patch
series and without an RFC tag. Do you want to hold off a bit to get
build coverage or go ahead and target net-next right away?

Thanks!
-- 
Florian

Re: [PATCH RFC v2 3/3] net: phy: allow EEE with SGMII interface modes

[Russell King - ARM Linux]

On Mon, Mar 27, 2017 at 03:42:57PM -0700, Florian Fainelli wrote:
> I think David will require you to resubmit this as an entire patch
> series and without an RFC tag. Do you want to hold off a bit to get
> build coverage or go ahead and target net-next right away?

I'd prefer to get build coverage first - there's no point in not using
the facilities that are available.

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.