Re: Meson8b network not stable at gigabit

[Aymeric <mulx@aplu.fr>]

Le 15/06/2019 à 13:34, Martin Blumenstingl a écrit :
> Hello Aymeric,
Hello Martin,
>
> On Sat, Jun 15, 2019 at 12:22 AM Aymeric <mulx@aplu.fr> wrote:
>> Hello all,
>>
>> I've just subscribe on this mailing list, so forgive me if I'm not
>> following some rules.
>>
>> Anyway, I've an ODROID-C1 board (which mean meson8b/S805) and I've some
>> network stability issue with both kernel 5.0.x and 5.1.x (as of today
>> I'm using 5.1.9, compiled myself - config file used is available here [¹]).
>>
>> The network card is detecting the link as down and up every few seconds
>> making it unusable.
> that is bad :(
> how do you trigger this problem?

I just boot the board with the network attached, I'm not doing anything
special.
I know a friend of mine, with the same board, we bought them together,
has the same issue than me.


>
>> The kernel from Hardkernel (3.10.something) is working fine.
> the 3.10 kernel uses polling for the PHY status while the mainline
> kernel uses an interrupt.
> that means 3.10 will only look for a link change every x milliseconds
> (I believe it's 500 or 1000 by default) while mainline will
> "instantly" detect any link change

Oh, okay, didn't know.


> can you please:
> 1. boot mainline Linux
> 2. bring eth0 up
> 3. run "cat /proc/interrupts | grep stmmac"
> 4. wait 1 minute, do not disconnect the network cable etc.
> 5. run "cat /proc/interrupts | grep stmmac" again

Just after boot, when I was able to login to the console,

$ uname -a
Linux odroid 5.2.0-rc4 #11 SMP PREEMPT Sat Jun 15 19:27:42 CEST 2019
armv7l GNU/Linux
$ cat /proc/interrupts | grep stmmac
 40:         12          0          0          0  meson-gpio-irqchip  17
Level     stmmac-0:00


And here is with one minute delay:

$ (date -R ;  cat /proc/interrupts | grep stmmac ; sleep 1m ; date -R ;
cat /proc/interrupts | grep stmmac )

Sun, 16 Jun 2019 17:22:00 +0200
 40:         32          0          0          0  meson-gpio-irqchip  17
Level     stmmac-0:00
Sun, 16 Jun 2019 17:23:00 +0200
 40:         47          0          0          0  meson-gpio-irqchip  17
Level     stmmac-0:00

> did you rule out the usual suspects (different switch port, try with
> another cable)?

I've tried indeed already try all other port of the switch (it's my
internet box) and an other network cable, with the same result.
But interestingly I've performed one more test today, by connecting the
odroid to an other switch (a D-LINK 8p gigabit) and there whatever cable
I use, the link became stable. This is strange as I've other PCs
directly connected to the internet box and working fine in gigabit…. and
the d-link and the internet box are in gigabit too.

The result from /proc/interrupts above are when I'm connected to my
operator box, from the d-link the value doesn't change any more.

According to the "about page" of the internet box, this is a Sagemcom
(Livebox 3).

So it look like there a incompatibility between the Realtek RTL8211F and
the "Sagemcom" but not with a "stupid" d-link switch….


-- 
Aymeric

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