Re: [PATCH v8 net-next 0/2] mv88e6xxx: Add MAB offload support

netdev
2022-11-18T13:39:10Z

On 2022-11-16 11:24, Vladimir Oltean wrote:
> On Tue, Nov 15, 2022 at 07:40:02PM +0100, netdev@kapio-technology.com
> wrote:
>> So, I will not present you with a graph as it is a tedious process
>> (probably
>> it is some descending gaussian curve wrt timeout occurring).
>>
>> But 100ms fails, 125 I had 1 port fail, at 140, 150 and 180 I saw
>> timeouts
>> resulting in fdb add fails, like (and occasional port fail):
>>
>> mv88e6085 1002b000.ethernet-1:04: Timeout while waiting for switch
>> mv88e6085 1002b000.ethernet-1:04: port 0 failed to add
>> be:7c:96:06:9f:09 vid
>> 1 to fdb: -110
>>
>> At around 200 ms it looks like it is getting stable (like 5 runs, no
>> problems).
>>
>> So with the gaussian curve tail whipping ones behind (risque of
>> failure) it
>> might need to be like 300 ms in my case... :-)
>
> Pick a value that is high enough to be reliable and submit a patch to
> "net" where you present the evidence for it (top-level MDIO controller,
> SoC, switch, kernel). I don't believe there's much to read into. A
> large
> timeout shouldn't have a negative effect on the MDIO performance,
> because it just determines how long it takes until the kernel declares
> it dead, rather than how long it takes for transactions to actually
> take
> place.

Would it not be appropriate to have a define that specifies the value
instead
of the same value two places as it is now?

And in so case, what would be an appropriate name?