2014-01-30 Max Filippov [off-list ref]:

On Wed, Jan 29, 2014 at 10:32 PM, Max Filippov [off-list ref] wrote:

quoted

On Wed, Jan 29, 2014 at 9:12 PM, Florian Fainelli [off-list ref] wrote:

quoted

On Jan 28, 2014 11:01 PM, "Max Filippov" [off-list ref] wrote:

quoted

On Wed, Jan 29, 2014 at 10:47 AM, Florian Fainelli [off-list ref]
wrote:

quoted

Hi Max,

Le 28/01/2014 22:00, Max Filippov a écrit :

quoted

OpenCores 10/100 Mbps MAC does not support speeds above 100 Mbps, but
does
not disable advertisement when PHY supports them. This results in
non-functioning network when the MAC is connected to a gigabit PHY
connected
to a gigabit switch.

The fix is to disable gigabit speed advertisement on attached PHY
unconditionally.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
Changes v1->v2:
- disable both gigabit advertisement and support.

  drivers/net/ethernet/ethoc.c | 8 ++++++++
  1 file changed, 8 insertions(+)

diff --git a/drivers/net/ethernet/ethoc.c

b/drivers/net/ethernet/ethoc.c
index 4de8cfd..5643b2d 100644

--- a/drivers/net/ethernet/ethoc.c
+++ b/drivers/net/ethernet/ethoc.c

@@ -688,6 +688,14 @@ static int ethoc_mdio_probe(struct net_device

*dev)
        }

        priv->phy = phy;
+       phy_update_advert(phy,
+                         ADVERTISED_1000baseT_Full |
+                         ADVERTISED_1000baseT_Half, 0);
+       phy_start_aneg(phy);

This does not look necessary, you should not have to call
phy_start_aneg()
because the PHY state machine is not yet started, at best this calls
does
nothing.

This call actually makes the whole thing work, because otherwise once
gigabit
support is cleared from the supported mask genphy_config_advert does not
update gigabit advertisement register, leaving it enabled.

OK, then we need to figure out what is wrong with ethoc since this is
unusual.

Maybe they boot up with gigabit advertisement disabled in their PHY
and thus they don't see the problem?

quoted

Other drivers do the following:

- connect to the PHY
- phydev->supported = PHY_BASIC_FEATURES
- phydev->advertising &= phydev->supported
- start the PHY state machine

And they work just fine. Is the PHY driver you are bound to the "Generic
PHY" or something else which does something funky in config_aneg()?

It's marvell 88E1111 from the KC-705 board, but the behaviour doesn't
change if I disable it and the generic phy is used.

Florian,

I don't see how the generic genphy_config_advert can ever change
gigabit advertisement if phydev->supported has gigabit speeds masked
off.

It does not, but it makes sure that phydev->advertising gets masked
with phydev->supported. So, prior to starting your PHY state machine,
if you do:

phydev->supported &= PHY_BASIC_FEATURES;
phydev->advertising = phydev->supported;

you should get the expected results. Just make sure that
phydev->autoneg is not set to AUTONEG_DISABLE, otherwise
phy_start_aneg() will not call phy_sanitize_settings(), and this might
be the problem.

So I'm pretty sure that other 10/100 cards would exhibit the same
issue if their PHY started with gigabit advertisement enabled.

If the speed is not restricted, yes that will be the case, but most
drivers seem to correctly set both phydev->supported and
phydev->advertising.

Maybe
we need to fix those other drivers? Or maybe we need to track what
PHY really supports vs. what we report it supports, so that gigabit
advertisement could be changed even when the PHY no longer
appears to support gigabit?

This is supposedly already taken care of provided that you correctly
restrict the PHY supported/advertising bits with respect to what the
HW really supports.
-- 
Florian