RE: [PATCH 1/2] stmmac: introduce flag to dynamically disable TX offload for rockchip devices

[Leonidas P. Papadakos]

ÎÏÎÏ ÎÎÏ, 3 ÎÏÏ, 2019 at 10:55 ÎÎ, Î/Î Jose Abreu 
<jose.abreu@xxxxxxxxxxxx> ÎÎÏÎÏÎ:
> From: Leonidas P. Papadakos <papadakospan@xxxxxxxxx>
> Date: Tue, Apr 02, 2019 at 23:48:16
>
> >  I can confirm that snps,no-pbl-x8, currently set by uboot for the 
> > fdt
> >  basically fixes the tx-checksumming issue.
> >  I get 700~800 Mbps myself but that might come down to the setup.
> >  You could say it affects performance slightly, as I saw in a 
> > previous
> >  email.
> >
> >  Without the setting The rate consistently drops to 0.
> >  ethtool reports tx-checksumming is on in both cases
> >
> >  Pretty cool!
> >  Does that give you guys an idea on how to tackle it "officially"?
>
> Thank you all for testing !
>
> It's been on my todo list to cook up a patch that limits PBL 
> according to
> FIFO size but I didn't manage to have the time yet so for now it would
> be better if you fix it by submitting the DT bindings changes.
>
> Thanks,
> Jose Miguel Abreu

If snps,no-pbl-x8 does indeed have a performace hit, should the 
workaround be to
a) turn tx checksumming off or
b) snps,no-pbl-x8 set?

I'll test to see the difference