From: Mason <slash.tmp@free•fr>
To: netdev <netdev@vger•kernel.org>
Cc: Florian Fainelli <f.fainelli@gmail•com>,
Mans Rullgard <mans@mansr•com>,
Sergei Shtylyov <sergei.shtylyov@cogentembedded•com>,
Tom Lendacky <thomas.lendacky@amd•com>,
Zach Brown <zach.brown@ni•com>, Andrew Lunn <andrew@lunn•ch>,
Shaohui Xie <shaohui.xie@nxp•com>,
Tim Beale <tim.beale@alliedtelesis•co.nz>,
Brian Hill <brian@houston-radar•com>,
Vince Bridgers <vbridgers2013@gmail•com>,
Balakumaran Kannan <kumaran.4353@gmail•com>,
"David S. Miller" <davem@davemloft•net>,
Sebastian Frias <sf84@laposte•net>,
Kirill Kapranov <kapranoff@inbox•ru>
Subject: Debugging Ethernet issues
Date: Sun, 13 Nov 2016 01:01:14 +0100 [thread overview]
Message-ID: <5827AD4A.7010908@free.fr> (raw)
Hello everyone,
In a past thread ("Ethernet not working on a different SoC with
same eth HW") I was struggling getting Ethernet to work at all on
a new board using a recent 4.7 kernel.
After much hair-pulling, it turned out that *some* of the breakage
was caused by a local patch which should have been guarded by a
preprocessor macro.
But even after reverting that patch, Ethernet does not work well
on this board with kernel 4.7 whereas if I use an ancient 3.4 kernel,
then Ethernet works much better.
Differences:
When connected to a 100 Mbps switch
3.4 negotiates a LAN DHCP setup instantly
4.7 times out
When connected to a Gigabit switch
3.4 negotiates a LAN DHCP setup instantly
4.7 requires over 5 seconds to do so
(In case it matters, my board is using an Atheros 8035 PHY.)
I am aware that there have been hundreds of patches to the phy
and net frameworks in the 3.4 to 4.7 time-frame. I'm wondering
if there are important events I can log, to see what is going
wrong in the 4.7 case?
Are there kernel debugging options I might turn on, to better
understand what is going wrong?
I would be extremely grateful for any insight on this subject.
Regards.
next reply other threads:[~2016-11-13 0:01 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-13 0:01 Mason [this message]
2016-11-13 3:09 ` Debugging Ethernet issues Andrew Lunn
2016-11-13 19:51 ` Mason
2016-11-13 19:55 ` Florian Fainelli
2016-11-14 13:03 ` Sebastian Frias
2016-11-14 13:28 ` Mason
2016-11-14 13:34 ` Andrew Lunn
2016-11-14 14:58 ` Mason
2016-11-14 15:33 ` Mason
2016-11-14 17:32 ` Florian Fainelli
2016-11-14 17:59 ` Sebastian Frias
2016-11-14 18:20 ` Florian Fainelli
2016-11-14 18:42 ` Florian Fainelli
2016-11-14 19:00 ` Måns Rullgård
2016-11-14 19:19 ` Florian Fainelli
2016-11-17 22:17 ` Måns Rullgård
2016-11-14 20:27 ` Mason
2016-11-14 21:00 ` Florian Fainelli
2016-11-14 22:48 ` Mason
2016-11-16 11:10 ` Sebastian Frias
2016-11-14 12:13 ` Mason
2016-11-14 12:45 ` Mason
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