23.03.2017 14:30, Maxime Morin пишет:
Hi,
Thank you very much for your help and your reactivity! See my answer bellow:
22.03.2017 16:23, Maxime Morin пишет:
Hi all,
I work on an embedded platform based on the Marvell Armada 88F6707, that is
connected to a Marvell Alaska 88E1512 ethernet transceiver. A defect has
appeared recently, and it turns out to be a regression on the network part.
There is a complete lost of the network when following these steps:
1) boot the board with the network cable disconnected
2) run the following commands (or equivalent):
ip link set eth0 up
ip addr add 10.0.0.80/24 dev eth0
ethtool -s eth0 autoneg on #this is the command that really breaks
the network
Why do you call it a regression, if previously
this command did nothing at all?
I called that a regression because we still pass through the function
phy_ethtool_sset(), which I though was also doing something about the
auto-negotiation. But apparently not.
It does, but with mdio.
But in the MAC driver we have another autoneg
now, which is a great confusion. mvneta_set_autoneg()
could have been named mvneta_set_inband_autoneg(),
which would already help a lot. If you prepare the patch-set,
you can include such renaming
I did a "git bisect" to find when the regression was introduced, because it
previously worked with kernel 4.4, but not with the recent ones. The commit that made
appear the issue is this one:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0c0744fc1dd5b
If I remove on mvneta.c the part that was added on this commit on the function
mvneta_ethtool_set_link_ksettings (mvneta_ethtool_set_settings at that time), I
do not have the issue, but I can't call that a fix...
So, could it be a driver issue, or maybe a wrong configuration somewhere? If
you need additional information to reproduce the problem please ask me, I will
be as responsive as possible.
It seems mvneta_set_autoneg() does some non-symmetric
things. It clears
MVNETA_GMAC_FORCE_LINK_PASS |
MVNETA_GMAC_FORCE_LINK_DOWN |
MVNETA_GMAC_AN_FLOW_CTRL_EN
when enabling autoneg, and does not restore these flags
when disabling it. Try to make it to set or to restore these
flags and see if that makes "ethtool -s eth0 autoneg off" to
get the network back alive> .
As you suggested, I just set these three flags when the function is called with
"enable" set to 0. And it works!
Am I right that it works only when you set autoneg
to "off", while "on" still does not give you any link detect?
So this is a partial fix, right?
Actually, I did not even have to set autoneg to off. When the module is probed, the
default param are applied (mvneta_defaults_set()), and mvneta_set_autoneg() is called
with "enable" to 0, and it seems to fix everything.
It turns off SGMII-specific autoned and starts using
mdio autoneg instead... a great confusion.
I tested it then, by setting autoneg to off/on, booting with or without the
cable plugged, and I failed to break it. It seems to be fixed. Should I submit
a patch? (would be the first time...)
After looking up my other patches to this driver, I
can see that
MVNETA_GMAC_FORCE_LINK_PASS |
MVNETA_GMAC_FORCE_LINK_DOWN
are left cleared willingly. I suspect that MVNETA_GMAC_AN_FLOW_CTRL_EN
breaks things for you. Could you please try with setting
back only this flag?
