[PATCH] ARM64: meson-gxl: disable broken eee

[Martin Blumenstingl]

On Mon, Jul 24, 2017 at 6:09 PM, Jerome Brunet <jbrunet at baylibre.com> wrote:
> On Mon, 2017-07-24 at 14:26 +0200, Neil Armstrong wrote:
>> On 07/24/2017 02:06 PM, Neil Armstrong wrote:
>> > On 07/23/2017 07:03 PM, Joseph Kogut wrote:
>> > > Hi Kevin,
>> > >
>> > > I tested on a P212 reference board, which is currently the only GXL
>> > > based board I have.
>> > >
>> > > Before applying the patch, high activity on the ethernet interface
>> > > would cause the link to break, requiring the interface to be brought
>> > > down and back up before it would work again. After applying the patch,
>> > > I could not get the link to break with any transfers.
>> > >
>> > > _______________________________________________
>> > > linux-arm-kernel mailing list
>> > > linux-arm-kernel at lists.infradead.org
>> > > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>> > >
>> >
>> > Hi Joseph,
>> >
>> > [please keep the history of the conversation when replying]
>> >
>> > Is it a original P212 board, or a board based on the P212 ref design ?
>> >
>> > I'm currently testing the v4.13-rc2 on the official P212 board we received
>> > from Amlogic
>> > and using iperf3 in both directions, I have an issue after a few minutes
>> > running iperf3 with :
>> >
>> > # while true ; do iperf3 -c 192.168.1.21 ; iperf3 -c 192.168.1.21 -R ; done
>> >
>> > That cycles between the two iperf directions.
>> >
>> > After a few minutes, it stalls with :
>> >
>> > Connecting to host 192.168.1.21, port 5201
>> > [  4] local 192.168.1.183 port 51286 connected to 192.168.1.21 port 5201
>> > [ ID] Interval           Transfer     Bandwidth       Retr  Cwnd
>> > [  4]   0.00-1.00   sec  1.64 MBytes  13.7 Mbits/sec    2   1.41 KBytes
>> > [  4]   1.00-2.00   sec  0.00 Bytes  0.00 bits/sec    1   1.41 KBytes
>> > [  4]   2.00-3.00   sec  0.00 Bytes  0.00 bits/sec    0   1.41 KBytes
>> > [  4]   3.00-4.00   sec  0.00 Bytes  0.00 bits/sec    1   1.41 KBytes
>> > [  4]   4.00-5.00   sec  0.00 Bytes  0.00 bits/sec    0   1.41 KBytes
>> > [  4]   5.00-6.00   sec  0.00 Bytes  0.00 bits/sec    0   1.41 KBytes
>> > [  4]   6.00-7.00   sec  0.00 Bytes  0.00 bits/sec    1   1.41 KBytes
>> > [  4]   7.00-8.00   sec  0.00 Bytes  0.00 bits/sec    0   1.41 KBytes
>> > [  4]   8.00-9.00   sec  0.00 Bytes  0.00 bits/sec    0   1.41 KBytes
>> >
>
> Same kind of test shows no issue on the libretech-cc and the khadas-vim
> In this case, I don't think meson-gxl.dtsi is where you should make your change.
>
>> >
>> > And then, after:
>> > # ifconfig eth0 down
>> > # ifconfig eth0 up
>> >
>> > It cycles between :
>> > [ 1483.009919] meson8b-dwmac c9410000.ethernet eth0: Link is Up -
>> > 100Mbps/Full - flow control rx/tx
>> > [ 1487.105725] meson8b-dwmac c9410000.ethernet eth0: Link is Down
>> > [ 1490.177943] meson8b-dwmac c9410000.ethernet eth0: Link is Up -
>> > 100Mbps/Full - flow control rx/tx
>> > [ 1494.273713] meson8b-dwmac c9410000.ethernet eth0: Link is Down
>
> This does not look like the issue we had on the odroid-c2.
> However, I have seen behavior like this (link down/up flickering) when the rgmii
>  delays are way off.
>
> Maybe you could try playing with "amlogic,tx-delay-ns" property ?
we need to change dwmac-meson8b.c so it applies the TX delay also for
RMII PHYs. currently the TX delay is always set to 0 for RMII PHYs,
see: [0]

>> >
>> > and so on.
>> >
>> > And this patch does not fix this at all.
>> >
>> > It seems to be more a PHY driver issue here.
>> >
>> > Could you share the results with the same command ?
>> >
>> > Neil
>> >
>>
>> I forgot to precise, this issue occurs when the "GXL PHY driver" is disabled,
>> only relying on the
>> Generic PHY Driver.
>>
>> [  630.767538] Generic PHY 0.e40908ff:08: attached PHY driver [Generic PHY]
>> (mii_bus:phy_addr=0.e40908ff:08, irq=-1)
>>
>>
>> When the PHY driver is loaded the issue disappears, with and without your
>> patch.
>>
>> [   25.355620] Meson GXL Internal PHY 0.e40908ff:08: attached PHY driver
>> [Meson GXL Internal PHY] (mii_bus:phy_addr=0.e40908ff:08, irq=-1)
>>
>> Could you please check the PHY Driver is loaded ?
>>
>> Thanks,
>> Neil
>
>
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[0] https://github.com/torvalds/linux/blob/master/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c#L222