Re: [PATCH] lan743x: Added fixed link and RGMII support / debugging

From: Roelof Berg
Date: Wed Jun 03 2020 - 12:33:43 EST


Ok, let's proceed :) The code runs well, dmesg looks good, ip addr shows me a link up, speed/duplex looks ok. But it does not transfer any data.

Debugging steps (A/B versions):
- Check clocks with oscilloscope (10/100/1000)
- Dump actual register settings
- Trace Phy-Phy autonegotiation and ensure that our patch catches up the result

Research topic:
I will also look if in my test hardware uses distinct MDIO traces or in-band MDIO (MDIO via MII). Would inband MDIO need the autosense feature to talk to the phy before phy-phy auto negotiation is complete ? E.g. for triggering phy-phy autoneg ? And is this (inband mdio) maybe the reason why the may-phy autosense feature exists in the silicon ?

Thanks,
Roelof

> Am 03.06.2020 um 17:59 schrieb Andrew Lunn <andrew@xxxxxxx>:
>
> On Wed, Jun 03, 2020 at 04:52:32PM +0200, Roelof Berg wrote:
>> TEST REPORT: BROKEN PATCH
>>
>> Thanks to everyone for working on the fixed link feature of lan743x eth driver.
>>
>
>> I received more test hardware today, and one piece of hardware
>> (EVBlan7430) becomes incompatible by the patch. We need to roll back
>> for now. Sorry.
>
> Hi Roelof
>
> We have a bit of time to fix this, before it becomes too critical.
> So lets try to fix it.
>
> How did it break?
>
> Thanks
> Andrew
>